LinuxQuestions.org - ATI x1600 AGP + Fglrx = Bus Setting: 0x

I installed the fglrx drivers for my ATI x1600 Pro AGP card to get DRI and it seems to work (UT: GOTY works fine) and I get the following output when I run fglrxinfo:

display: :0.0 screen: 0
OpenGL vendor string: ATI Technologies Inc.
OpenGL renderer string: Radeon X1600 Series
OpenGL version string: 2.0.6474 (8.38.6)

However, some 2D drawing operations are very slow. For example, when I open K3B, the background image takes about 1 second to get drawn. Another example is when I open the Log Out dialog in Kubuntu, the background slowly fades but it's not smooth like on my others computers. The dark overlay appears in chunks. Compiz/Beryl are also VERY slow when I resize a window or when I minimize/maximize (it takes about 2 secs before something happens when I maximize a window). I started investigating the problem and found 2 things.

1 - In ATI catalyst control center, Bus Setting is 0x
2 - In my Xorg.0.log:

(II) LoadModule: "fglrxdrm"
(II) Loading /usr/lib/xorg/modules/linux//libfglrxdrm.so
(II) Module fglrxdrm: vendor="FireGL - ATI Technologies Inc."
compiled for 7.1.0, module version = 8.38.6
ABI class: X.Org Server Extension, version 0.3
(--) fglrx(0): VideoRAM: 262144 kByte, Type: DDR2
(II) fglrx(0): PCIE card detected

Notice "PCIE card detected"... My x1600 is AGP...

I had a third problem before. When I used to cat /proc/mtrr I had all 8 registers used, 7 of which when in video memory (small chunks of increasing size in powers of 2 in video memory: 256k, 512k, 1mb, 2mb...). I fixed this by adding Option "mtrr" "off" in my xorg.conf but I'm not sure if it's a good solution.

Here's my xorg.conf, but I doubt it's something in there since I tried almost every possible combination of options.

Section "Files"
FontPath "/usr/share/fonts/X11/misc"
FontPath "/usr/share/fonts/X11/cyrillic"
FontPath "/usr/share/fonts/X11/100dpi/:unscaled"
FontPath "/usr/share/fonts/X11/75dpi/:unscaled"
FontPath "/usr/share/fonts/X11/Type1"
FontPath "/usr/share/fonts/X11/100dpi"
FontPath "/usr/share/fonts/X11/75dpi"
# path to defoma fonts
FontPath "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
Load "bitmap"
Load "dbe"
Load "ddc"
Load "dri"
Load "extmod"
Load "freetype"
Load "glx"
Load "int10"
Load "vbe"
EndSection

Section "InputDevice"
Identifier "Generic Keyboard"
Driver "kbd"
Option "CoreKeyboard"
Option "XkbRules" "xorg"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
Option "XkbOptions" "lv3:ralt_switch"
EndSection

Section "InputDevice"
Identifier "Configured Mouse"
Driver "mouse"
Option "CorePointer"
Option "Device" "/dev/input/mice"
Option "Protocol" "ExplorerPS/2"
Option "Buttons" "7"
Option "ButtonMapping" "1 2 3 6 7"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "false"
EndSection

Section "ServerFlags"
Option "AIGLX" "off"
EndSection

Section "Device"
Identifier "ATI X1600 Pro"
Driver "fglrx"
BusID "PCI:1:0:0"
Option "UseFBDev" "true"
Option "VideoOverlay" "on"
Option "mtrr" "off"
EndSection

Section "Extensions"
Option "Composite" "0"
EndSection

Section "Monitor"
Identifier "Generic Monitor"
Option "DPMS"
DisplaySize 338 270 # 1280x1024 96dpi
EndSection

Section "Screen"
Identifier "Default Screen"
Device "ATI X1600 Pro"
Monitor "Generic Monitor"
DefaultDepth 24
SubSection "Display"
Depth 1
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024" "1024x768" "800x600" "640x480"
EndSubSection
EndSection

Section "ServerLayout"
Identifier "Default Layout"
Screen "Default Screen"
InputDevice "Generic Keyboard"
InputDevice "Configured Mouse"
EndSection

Section "DRI"
Mode 0666
EndSection

Thanks for your help!