Nvidia graphics in Gentoo

[zedro]

I have a nvidia GeForce4 Ti4600 and run Gentoo with 2.6.4 Gentoo kernel.

I installed the latest IA32 Linux drivers fine (1.0.5536), and replaced the kernel module from the old driver but in X there are problems with color blending. The graphics are extremely grainy wherever there is any sort of shading (dithering on kicker in KDE or jpegs for instance). It isn't quite pixelated, but there are spotty pixels all over areas like this. Solid colors are fine. Anyway, here is my XF86Config:

Section "ServerLayout"
Identifier "XFree86 Configured"
Screen 0 "Screen0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
RgbPath "/usr/X11R6/lib/X11/rgb"
ModulePath "/usr/X11R6/lib/modules"
FontPath "/usr/X11R6/lib/X11/fonts/misc/"
FontPath "/usr/X11R6/lib/X11/fonts/Speedo/"
FontPath "/usr/X11R6/lib/X11/fonts/Type1/"
FontPath "/usr/X11R6/lib/X11/fonts/CID/"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi/"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi/"
EndSection

Section "Module"
Load "extmod"
#Load "dri"
Load "dbe"
Load "record"
Load "xtrap"
Load "glx"
Load "speedo"
Load "type1"
EndSection

Section "InputDevice"
Identifier "Keyboard0"
Driver "keyboard"
EndSection

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "IMPS/2"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
EndSection

Section "Monitor"
#DisplaySize 360 290 # mm
Identifier "Monitor0"
VendorName "DEL"
ModelName "DELL 1800FP"
HorizSync 50-80
VertRefresh 43-75
Option "DPMS"
EndSection

Section "Device"
### Available Driver options are:-
### Values: <i>: integer, <f>: float, <bool>: "True"/"False",
### <string>: "String", <freq>: "<f> Hz/kHz/MHz"
### [arg]: arg optional
#Option "SWcursor" # [<bool>]
#Option "HWcursor" # [<bool>]
#Option "NoAccel" # [<bool>]
#Option "ShowCache" # [<bool>]
#Option "ShadowFB" # [<bool>]
#Option "UseFBDev" # [<bool>]
#Option "Rotate" # [<str>]
#Option "VideoKey" # <i>
Option "FlatPanel" "True" # [<bool>]
#Option "FPDither" # [<bool>]
#Option "CrtcNumber" # <i>
Identifier "Card0"
#Driver "nv"
Driver "nvidia"
VendorName "nVidia Corporation"
BoardName "NV25 [GeForce4 Ti 4600]"
#BusID "PCI:1:0:0"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
SubSection "Display"
Depth 1
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 4
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 8
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 15
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 16
Modes "1280x1024" "1024x768" "800x600"
EndSubSection
SubSection "Display"
Depth 24
Modes "1280x1024"
EndSubSection
EndSection

I think this is probably a Gentoo problem, since the card and drivers worked fine in Mandrake 9.2. Also, I had the same problem with the 1.0.4480 drivers distributed with Gentoo. But if anyone has any idea what I could do, I'd appreciate any suggestions.
Thanks in advance.