Hello there!
I'm using Ubuntu 10.10 now and I have to get connected with the projector.
I have dual boot with Windows, in which everything is working fine, but with Ubuntu, the moment I reach login screen after booting, it drops the signal.
I saw a similar thread but with ATI card and my problem is with nvidia. So posted a fresh one.
My laptop is ThinkPad T61p and has nvidia graphics.

Please help me how do I resolve this.

---------- Post added 11-10-11 at 10:43 AM ----------

Output of xrandr --verbose:

dbs@dbs-pc:~$ xrandr --verbose
xrandr: Failed to get size of gamma for output default
Screen 0: minimum 320 x 175, current 1920 x 1200, maximum 1920 x 1200
default connected 1920x1200+0+0 (0x281) normal (normal) 0mm x 0mm
Identifier: 0x280
Timestamp: 72358
Subpixel: unknown
Clones:
CRTC: 0
CRTCs: 0
Transform: 1.000000 0.000000 0.000000
0.000000 1.000000 0.000000
0.000000 0.000000 1.000000
filter:
1920x1200 (0x281) 115.2MHz *current
h: width 1920 start 0 end 0 total 1920 skew 0 clock 60.0KHz
v: height 1200 start 0 end 0 total 1200 clock 50.0Hz
1920x1200 (0x282) 117.5MHz
h: width 1920 start 0 end 0 total 1920 skew 0 clock 61.2KHz
v: height 1200 start 0 end 0 total 1200 clock 51.0Hz
1920x1200 (0x283) 119.8MHz
h: width 1920 start 0 end 0 total 1920 skew 0 clock 62.4KHz
v: height 1200 start 0 end 0 total 1200 clock 52.0Hz
1920x1200 (0x284) 122.1MHz
h: width 1920 start 0 end 0 total 1920 skew 0 clock 63.6KHz
v: height 1200 start 0 end 0 total 1200 clock 53.0Hz
1920x1080 (0x285) 112.0MHz
h: width 1920 start 0 end 0 total 1920 skew 0 clock 58.3KHz
v: height 1080 start 0 end 0 total 1080 clock 54.0Hz
1680x1050 (0x286) 97.0MHz
h: width 1680 start 0 end 0 total 1680 skew 0 clock 57.8KHz
v: height 1050 start 0 end 0 total 1050 clock 55.0Hz
1680x1050 (0x287) 98.8MHz
h: width 1680 start 0 end 0 total 1680 skew 0 clock 58.8KHz
v: height 1050 start 0 end 0 total 1050 clock 56.0Hz
1600x1200 (0x288) 109.4MHz
h: width 1600 start 0 end 0 total 1600 skew 0 clock 68.4KHz
v: height 1200 start 0 end 0 total 1200 clock 57.0Hz
1600x1024 (0x289) 95.0MHz
h: width 1600 start 0 end 0 total 1600 skew 0 clock 59.4KHz
v: height 1024 start 0 end 0 total 1024 clock 58.0Hz
1440x900 (0x28a) 76.5MHz
h: width 1440 start 0 end 0 total 1440 skew 0 clock 53.1KHz
v: height 900 start 0 end 0 total 900 clock 59.0Hz
1400x1050 (0x28b) 88.2MHz
h: width 1400 start 0 end 0 total 1400 skew 0 clock 63.0KHz
v: height 1050 start 0 end 0 total 1050 clock 60.0Hz
1400x1050 (0x28c) 89.7MHz
h: width 1400 start 0 end 0 total 1400 skew 0 clock 64.0KHz
v: height 1050 start 0 end 0 total 1050 clock 61.0Hz
1400x1050 (0x28d) 91.1MHz
h: width 1400 start 0 end 0 total 1400 skew 0 clock 65.1KHz
v: height 1050 start 0 end 0 total 1050 clock 62.0Hz
1360x768 (0x28e) 65.8MHz
h: width 1360 start 0 end 0 total 1360 skew 0 clock 48.4KHz
v: height 768 start 0 end 0 total 768 clock 63.0Hz
1360x768 (0x28f) 66.8MHz
h: width 1360 start 0 end 0 total 1360 skew 0 clock 49.2KHz
v: height 768 start 0 end 0 total 768 clock 64.0Hz
1280x1024 (0x290) 85.2MHz
h: width 1280 start 0 end 0 total 1280 skew 0 clock 66.6KHz
v: height 1024 start 0 end 0 total 1024 clock 65.0Hz
1280x1024 (0x291) 86.5MHz
h: width 1280 start 0 end 0 total 1280 skew 0 clock 67.6KHz
v: height 1024 start 0 end 0 total 1024 clock 66.0Hz
1280x1024 (0x292) 87.8MHz
h: width 1280 start 0 end 0 total 1280 skew 0 clock 68.6KHz
v: height 1024 start 0 end 0 total 1024 clock 67.0Hz
1280x960 (0x293) 83.6MHz
h: width 1280 start 0 end 0 total 1280 skew 0 clock 65.3KHz
v: height 960 start 0 end 0 total 960 clock 68.0Hz
1280x960 (0x294) 84.8MHz
h: width 1280 start 0 end 0 total 1280 skew 0 clock 66.2KHz
v: height 960 start 0 end 0 total 960 clock 69.0Hz
1152x864 (0x295) 69.7MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 60.5KHz
v: height 864 start 0 end 0 total 864 clock 70.0Hz
1152x864 (0x296) 70.7MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 61.3KHz
v: height 864 start 0 end 0 total 864 clock 71.0Hz
1152x864 (0x297) 71.7MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 62.2KHz
v: height 864 start 0 end 0 total 864 clock 72.0Hz
1152x864 (0x298) 72.7MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 63.1KHz
v: height 864 start 0 end 0 total 864 clock 73.0Hz
1152x864 (0x299) 73.7MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 63.9KHz
v: height 864 start 0 end 0 total 864 clock 74.0Hz
1152x864 (0x29a) 74.6MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 64.8KHz
v: height 864 start 0 end 0 total 864 clock 75.0Hz
1152x864 (0x29b) 75.6MHz
h: width 1152 start 0 end 0 total 1152 skew 0 clock 65.7KHz
v: height 864 start 0 end 0 total 864 clock 76.0Hz
1024x768 (0x29c) 60.6MHz
h: width 1024 start 0 end 0 total 1024 skew 0 clock 59.1KHz
v: height 768 start 0 end 0 total 768 clock 77.0Hz
1024x768 (0x29d) 61.3MHz
h: width 1024 start 0 end 0 total 1024 skew 0 clock 59.9KHz
v: height 768 start 0 end 0 total 768 clock 78.0Hz
1024x768 (0x29e) 62.1MHz
h: width 1024 start 0 end 0 total 1024 skew 0 clock 60.7KHz
v: height 768 start 0 end 0 total 768 clock 79.0Hz
1024x768 (0x29f) 62.9MHz
h: width 1024 start 0 end 0 total 1024 skew 0 clock 61.4KHz
v: height 768 start 0 end 0 total 768 clock 80.0Hz
1024x768 (0x2a0) 63.7MHz
h: width 1024 start 0 end 0 total 1024 skew 0 clock 62.2KHz
v: height 768 start 0 end 0 total 768 clock 81.0Hz
1024x768 (0x2a1) 64.5MHz
h: width 1024 start 0 end 0 total 1024 skew 0 clock 63.0KHz
v: height 768 start 0 end 0 total 768 clock 82.0Hz
960x720 (0x2a2) 57.4MHz
h: width 960 start 0 end 0 total 960 skew 0 clock 59.8KHz
v: height 720 start 0 end 0 total 720 clock 83.0Hz
960x720 (0x2a3) 58.1MHz
h: width 960 start 0 end 0 total 960 skew 0 clock 60.5KHz
v: height 720 start 0 end 0 total 720 clock 84.0Hz
960x600 (0x2a4) 49.0MHz
h: width 960 start 0 end 0 total 960 skew 0 clock 51.0KHz
v: height 600 start 0 end 0 total 600 clock 85.0Hz
960x540 (0x2a5) 44.6MHz
h: width 960 start 0 end 0 total 960 skew 0 clock 46.4KHz
v: height 540 start 0 end 0 total 540 clock 86.0Hz
928x696 (0x2a6) 56.2MHz
h: width 928 start 0 end 0 total 928 skew 0 clock 60.6KHz
v: height 696 start 0 end 0 total 696 clock 87.0Hz
928x696 (0x2a7) 56.8MHz
h: width 928 start 0 end 0 total 928 skew 0 clock 61.2KHz
v: height 696 start 0 end 0 total 696 clock 88.0Hz
896x672 (0x2a8) 53.6MHz
h: width 896 start 0 end 0 total 896 skew 0 clock 59.8KHz
v: height 672 start 0 end 0 total 672 clock 89.0Hz
896x672 (0x2a9) 54.2MHz
h: width 896 start 0 end 0 total 896 skew 0 clock 60.5KHz
v: height 672 start 0 end 0 total 672 clock 90.0Hz
840x525 (0x2aa) 40.1MHz
h: width 840 start 0 end 0 total 840 skew 0 clock 47.8KHz
v: height 525 start 0 end 0 total 525 clock 91.0Hz
840x525 (0x2ab) 40.6MHz
h: width 840 start 0 end 0 total 840 skew 0 clock 48.3KHz
v: height 525 start 0 end 0 total 525 clock 92.0Hz
840x525 (0x2ac) 41.0MHz
h: width 840 start 0 end 0 total 840 skew 0 clock 48.8KHz
v: height 525 start 0 end 0 total 525 clock 93.0Hz
840x525 (0x2ad) 41.5MHz
h: width 840 start 0 end 0 total 840 skew 0 clock 49.4KHz
v: height 525 start 0 end 0 total 525 clock 94.0Hz
840x525 (0x2ae) 41.9MHz
h: width 840 start 0 end 0 total 840 skew 0 clock 49.9KHz
v: height 525 start 0 end 0 total 525 clock 95.0Hz
832x624 (0x2af) 49.8MHz
h: width 832 start 0 end 0 total 832 skew 0 clock 59.9KHz
v: height 624 start 0 end 0 total 624 clock 96.0Hz
800x600 (0x2b0) 46.6MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 58.2KHz
v: height 600 start 0 end 0 total 600 clock 97.0Hz
800x600 (0x2b1) 47.0MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 58.8KHz
v: height 600 start 0 end 0 total 600 clock 98.0Hz
800x600 (0x2b2) 47.5MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 59.4KHz
v: height 600 start 0 end 0 total 600 clock 99.0Hz
800x600 (0x2b3) 48.0MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 60.0KHz
v: height 600 start 0 end 0 total 600 clock 100.0Hz
800x600 (0x2b4) 48.5MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 60.6KHz
v: height 600 start 0 end 0 total 600 clock 101.0Hz
800x600 (0x2b5) 49.0MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 61.2KHz
v: height 600 start 0 end 0 total 600 clock 102.0Hz
800x600 (0x2b6) 49.4MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 61.8KHz
v: height 600 start 0 end 0 total 600 clock 103.0Hz
800x600 (0x2b7) 49.9MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 62.4KHz
v: height 600 start 0 end 0 total 600 clock 104.0Hz
800x600 (0x2b8) 50.4MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 63.0KHz
v: height 600 start 0 end 0 total 600 clock 105.0Hz
800x600 (0x2b9) 50.9MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 63.6KHz
v: height 600 start 0 end 0 total 600 clock 106.0Hz
800x512 (0x2ba) 43.8MHz
h: width 800 start 0 end 0 total 800 skew 0 clock 54.8KHz
v: height 512 start 0 end 0 total 512 clock 107.0Hz
720x450 (0x2bb) 35.0MHz
h: width 720 start 0 end 0 total 720 skew 0 clock 48.6KHz
v: height 450 start 0 end 0 total 450 clock 108.0Hz
720x400 (0x2bc) 31.4MHz
h: width 720 start 0 end 0 total 720 skew 0 clock 43.6KHz
v: height 400 start 0 end 0 total 400 clock 109.0Hz
700x525 (0x2bd) 40.4MHz
h: width 700 start 0 end 0 total 700 skew 0 clock 57.8KHz
v: height 525 start 0 end 0 total 525 clock 110.0Hz
700x525 (0x2be) 40.8MHz
h: width 700 start 0 end 0 total 700 skew 0 clock 58.3KHz
v: height 525 start 0 end 0 total 525 clock 111.0Hz
700x525 (0x2bf) 41.2MHz
h: width 700 start 0 end 0 total 700 skew 0 clock 58.8KHz
v: height 525 start 0 end 0 total 525 clock 112.0Hz
700x525 (0x2c0) 41.5MHz
h: width 700 start 0 end 0 total 700 skew 0 clock 59.3KHz
v: height 525 start 0 end 0 total 525 clock 113.0Hz
680x384 (0x2c1) 29.8MHz
h: width 680 start 0 end 0 total 680 skew 0 clock 43.8KHz
v: height 384 start 0 end 0 total 384 clock 114.0Hz
680x384 (0x2c2) 30.0MHz
h: width 680 start 0 end 0 total 680 skew 0 clock 44.2KHz
v: height 384 start 0 end 0 total 384 clock 115.0Hz
640x512 (0x2c3) 38.0MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 59.4KHz
v: height 512 start 0 end 0 total 512 clock 116.0Hz
640x512 (0x2c4) 38.3MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 59.9KHz
v: height 512 start 0 end 0 total 512 clock 117.0Hz
640x512 (0x2c5) 38.7MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 60.4KHz
v: height 512 start 0 end 0 total 512 clock 118.0Hz
640x480 (0x2c6) 36.6MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 57.1KHz
v: height 480 start 0 end 0 total 480 clock 119.0Hz
640x480 (0x2c7) 36.9MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 57.6KHz
v: height 480 start 0 end 0 total 480 clock 120.0Hz
640x480 (0x2c8) 37.2MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 58.1KHz
v: height 480 start 0 end 0 total 480 clock 121.0Hz
640x480 (0x2c9) 37.5MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 58.6KHz
v: height 480 start 0 end 0 total 480 clock 122.0Hz
640x480 (0x2ca) 37.8MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 59.0KHz
v: height 480 start 0 end 0 total 480 clock 123.0Hz
640x480 (0x2cb) 38.1MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 59.5KHz
v: height 480 start 0 end 0 total 480 clock 124.0Hz
640x400 (0x2cc) 32.0MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 50.0KHz
v: height 400 start 0 end 0 total 400 clock 125.0Hz
640x350 (0x2cd) 28.2MHz
h: width 640 start 0 end 0 total 640 skew 0 clock 44.1KHz
v: height 350 start 0 end 0 total 350 clock 126.0Hz
576x432 (0x2ce) 31.6MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 54.9KHz
v: height 432 start 0 end 0 total 432 clock 127.0Hz
576x432 (0x2cf) 31.9MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 55.3KHz
v: height 432 start 0 end 0 total 432 clock 128.0Hz
576x432 (0x2d0) 32.1MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 55.7KHz
v: height 432 start 0 end 0 total 432 clock 129.0Hz
576x432 (0x2d1) 32.3MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 56.2KHz
v: height 432 start 0 end 0 total 432 clock 130.0Hz
576x432 (0x2d2) 32.6MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 56.6KHz
v: height 432 start 0 end 0 total 432 clock 131.0Hz
576x432 (0x2d3) 32.8MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 57.0KHz
v: height 432 start 0 end 0 total 432 clock 132.0Hz
576x432 (0x2d4) 33.1MHz
h: width 576 start 0 end 0 total 576 skew 0 clock 57.5KHz
v: height 432 start 0 end 0 total 432 clock 133.0Hz
512x384 (0x2d5) 26.3MHz
h: width 512 start 0 end 0 total 512 skew 0 clock 51.5KHz
v: height 384 start 0 end 0 total 384 clock 134.0Hz
512x384 (0x2d6) 26.5MHz
h: width 512 start 0 end 0 total 512 skew 0 clock 51.8KHz
v: height 384 start 0 end 0 total 384 clock 135.0Hz
512x384 (0x2d7) 26.7MHz
h: width 512 start 0 end 0 total 512 skew 0 clock 52.2KHz
v: height 384 start 0 end 0 total 384 clock 136.0Hz
512x384 (0x2d8) 26.9MHz
h: width 512 start 0 end 0 total 512 skew 0 clock 52.6KHz
v: height 384 start 0 end 0 total 384 clock 137.0Hz
512x384 (0x2d9) 27.1MHz
h: width 512 start 0 end 0 total 512 skew 0 clock 53.0KHz
v: height 384 start 0 end 0 total 384 clock 138.0Hz
416x312 (0x2da) 18.0MHz
h: width 416 start 0 end 0 total 416 skew 0 clock 43.4KHz
v: height 312 start 0 end 0 total 312 clock 139.0Hz
400x300 (0x2db) 16.8MHz
h: width 400 start 0 end 0 total 400 skew 0 clock 42.0KHz
v: height 300 start 0 end 0 total 300 clock 140.0Hz
400x300 (0x2dc) 16.9MHz
h: width 400 start 0 end 0 total 400 skew 0 clock 42.3KHz
v: height 300 start 0 end 0 total 300 clock 141.0Hz
400x300 (0x2dd) 17.0MHz
h: width 400 start 0 end 0 total 400 skew 0 clock 42.6KHz
v: height 300 start 0 end 0 total 300 clock 142.0Hz
400x300 (0x2de) 17.2MHz
h: width 400 start 0 end 0 total 400 skew 0 clock 42.9KHz
v: height 300 start 0 end 0 total 300 clock 143.0Hz
400x300 (0x2df) 17.3MHz
h: width 400 start 0 end 0 total 400 skew 0 clock 43.2KHz
v: height 300 start 0 end 0 total 300 clock 144.0Hz
360x200 (0x2e0) 10.4MHz
h: width 360 start 0 end 0 total 360 skew 0 clock 29.0KHz
v: height 200 start 0 end 0 total 200 clock 145.0Hz
320x240 (0x2e1) 11.2MHz
h: width 320 start 0 end 0 total 320 skew 0 clock 35.0KHz
v: height 240 start 0 end 0 total 240 clock 146.0Hz
320x240 (0x2e2) 11.3MHz
h: width 320 start 0 end 0 total 320 skew 0 clock 35.3KHz
v: height 240 start 0 end 0 total 240 clock 147.0Hz
320x240 (0x2e3) 11.4MHz
h: width 320 start 0 end 0 total 320 skew 0 clock 35.5KHz
v: height 240 start 0 end 0 total 240 clock 148.0Hz
320x240 (0x2e4) 11.4MHz
h: width 320 start 0 end 0 total 320 skew 0 clock 35.8KHz
v: height 240 start 0 end 0 total 240 clock 149.0Hz
320x200 (0x2e5) 9.6MHz
h: width 320 start 0 end 0 total 320 skew 0 clock 30.0KHz
v: height 200 start 0 end 0 total 200 clock 150.0Hz
320x175 (0x2e6) 8.5MHz
h: width 320 start 0 end 0 total 320 skew 0 clock 26.4KHz
v: height 175 start 0 end 0 total 175 clock 151.0Hz

The first thing that comes to mind for me, is that you may be trying to use a combination of resolutions/refresh rates between your monitor and projector that aren't supported by your linux driver. do you know if you're using a FOSS driver, or the proprietary NVidia driver?

Haylo akhuthia,
I guess I'm using proprietary Nvidia driver, but I'm not sure on this.
Is there is any way to check this?

I beleive there is a way, but i'm forgetting what it is, cuz i still suck at linux