nvidia 7400显卡问题！！

小弟的gentoo X 服务器的配置如下
Section "ServerLayout"
Identifier "X.org Configured"
Screen 0 "Screen0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
ModulePath "/usr/lib64/xorg/modules"
FontPath "/usr/share/fonts/misc/"
#FontPath "/usr/share/fonts/TTF/"
#FontPath "/usr/share/fonts/OTF"
FontPath "/usr/share/fonts/Type1/"
FontPath "/usr/share/fonts/100dpi/"
FontPath "/usr/share/fonts/75dpi/"
FontPath "/usr/share/fonts/wqy-bitmapfont/"
Fontpath "/usr/share/fonts/ttf-bitstream-vera/"
EndSection

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

Section "InputDevice"
Identifier "Keyboard0"
Driver "kbd"
EndSection

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "auto"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5 6 7"
EndSection

Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Monitor Model"
HorizSync 28.0 - 60.0
VertRefresh 43.0 - 60.0
Option "DPMS"
EndSection

Section "Device"
Identifier "Card0"
Driver "nvidia"
VendorName "nVidia Corporation"
BoardName "G72M [GeForce Go 7400]"
Option "NoLogo" "true"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultDepth 24
Option "AddARGBGLXVisuals" "true"
Option "RenderAccel"
SubSection "Display"
Viewport 0 0
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 4
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 8
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 15
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 16
EndSubSection
SubSection "Display"
Viewport 0 0
Depth 24
EndSubSection
EndSection

Section "ServerFlags"
Option "AllowEmpty" "false"
EndSection

Section "Extensions"
Option "Composite" "On"
EndSection
在进入非跟用户下，开启xfce4.6桌面后就会出现不定时的死机现象，如果换用nv的参数，就不会出现这个问题，不知道怎么解决它，看了好多文档，还是不能解决，不知道什么问题。
还有就是，如果在xfce桌面下屏幕抖动过，就无法回到文本模式的终端了，alt＋ctrl＋fn后进入的终端是黑屏。有那位知道怎么解决吗。