Good afternoon.

I have a Dell Inspiron 4150 laptop dual-booting Windows XP and Debian Linux Sarge. Ever since xserver-xorg replaced xserver-xfree86 in the debian packages I have had problems with the xserver when I try and break from KDE back to a terminal (ie.ctrl+alt+F1). The xserver does not hang as such, but when it attempts to change resolution to match that of the terminal I get a static display in black and white, showing the upper left corner of part of the KDE desktop. When I F7 back to the kde display a vertical quarter is repeated 4 times across the screen in very poor quality, with horizontal lines repeating down the screen. The only way I can recover from these symptoms is rebooting the laptop via SSH. It is worth mentioning that KDE works perfectly before trying to switch to a terminal, responding to resolution changes with no complaints.

The graphics card is an ATI Mobility Radeon 7500 using the "ati" driver specified when I ran xorg reconfigure. Kernel is a recent build at 2.6.17.8. The xserver does not report any errors to Xorg.0.log while the problem occurs, nor does kdm.log:
(**) RADEON(0): RADEONSaveScreen(2)
(**) RADEON(0): EngineRestore (32/32)
(**) RADEON(0): RADEONSwitchMode() !n(**) RADEON(0): EngineRestore (32/32)
(**) RADEON(0): RADEONLeaveVT
(**) RADEON(0): EngineRestore (32/32)
(**) RADEON(0): RADEONRestore
(**) RADEON(0): Ok, leaving now...
(**) RADEON(0): RADEONEnterVT
(II) RADEON(0): [RESUME] Attempting to re-init Radeon hardware.
(II) RADEON(0): [agp] Mode 0x1f000201 [AGP 0x8086/0x1a30; Card 0x1002/0x4c57]
(**) RADEON(0): EngineRestore (32/32)
(**) RADEON(0): EngineRestore (32/32)
(**) RADEON(0): RADEONSaveScreen(2)
(II) Configured Mouse: ps2EnableDataReporting: succeeded

Any help or advice would be greatly appreciated.

If you are able to log in remotely when the display is un-useable you can also check those logs remotely isn't it?

I know... that is how i got the logs. The system doesn't hang, just the xserver.

I have changed all the resolutions in xorg.conf from 1600x1200 to 1280x760. Now when i try and reach TTY1 the same symptoms occur but i can bring back TTY7(Kde) with no issues. This leads me to believe that xorg is trying to display TTY1-6 in a resolution or refresh rate which my laptop cannot handle. Would anyone else agree with this?

How can i define the resolution xorg switches me too?

Still on XFree86 here, so no idea's about Xorg. Sorry

my problem is very simular to yours, and i can't fix it the last two years.it's an ati driver bug, and it is supposed to have been fixed....
the only solution for me was to force agp 1x and disable fast writes with the following option in /etc/X11/xorg.conf :

Option "AGPMask" "0x00000016"

try writing it in section device for the fglrx. i hope it helps