your problem is where your TwinView options and whatnot go - they should be inside the Device section - let me know if you want to know what any of the options mean... here it is...
l
# XFree86 4 configuration created by maitre
Section "ServerLayout"
Identifier "Default Layout"
Screen 0 "Screen0" 0 0
InputDevice "Mouse0" "CorePointer"
InputDevice "Keyboard0" "CoreKeyboard"
EndSection
Section "Files"
# RgbPath is the location of the RGB database. Note, this is the name of the
# file minus the extension (like ".txt" or ".db"). There is normally
# no need to change the default.
# Multiple FontPath entries are allowed (they are concatenated together)
# By default, Red Hat 6.0 and later now use a font server independent of
# the X server to render fonts.
RgbPath "/usr/X11R6/lib/X11/rgb"
FontPath "unix/:7100"
EndSection
Section "Module"
Load "dbe"
Load "extmod"
Load "glx"
Load "record"
Load "freetype"
Load "type1"
Load "ramdac"
EndSection
Section "InputDevice"
# Specify which keyboard LEDs can be user-controlled (eg, with xset(1))
# Option "Xleds" "1 2 3"
# To disable the XKEYBOARD extension, uncomment XkbDisable.
# Option "XkbDisable"
# To customise the XKB settings to suit your keyboard, modify the
# lines below (which are the defaults). For example, for a non-U.S.
# keyboard, you will probably want to use:
# Option "XkbModel" "pc102"
# If you have a US Microsoft Natural keyboard, you can use:
# Option "XkbModel" "microsoft"
#
# Then to change the language, change the Layout setting.
# For example, a german layout can be obtained with:
# Option "XkbLayout" "de"
# or:
# Option "XkbLayout" "de"
# Option "XkbVariant" "nodeadkeys"
#
# If you'd like to switch the positions of your capslock and
# control keys, use:
# Option "XkbOptions" "ctrl:swapcaps"
# Or if you just want both to be control, use:
# Option "XkbOptions" "ctrl:nocaps"
#
Identifier "Keyboard0"
Driver "keyboard"
Option "XkbRules" "xfree86"
Option "XkbModel" "pc105"
Option "XkbLayout" "us"
EndSection
Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "IMPS/2"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "yes"
EndSection
Section "InputDevice"
# If the normal CorePointer mouse is not a USB mouse then
# this input device can be used in AlwaysCore mode to let you
# also use USB mice at the same time.
Identifier "DevInputMice"
Driver "mouse"
Option "Protocol" "IMPS/2"
Option "Device" "/dev/input/mice"
Option "ZAxisMapping" "4 5"
Option "Emulate3Buttons" "no"
EndSection
Section "Monitor"
Identifier "Monitor0"
VendorName "Monitor Vendor"
ModelName "Unprobed Monitor"
HorizSync 30.0 - 85.0
VertRefresh 50.0 - 160.0
Option "dpms" "off"
#Modeline "1152x864" 108 1152 1216 1344 1600 864 865 868 900 +hsync +vsync
#Modeline "1152x864" 185 1152 1216 1344 1600 864 865 868 900 +hsync +vsync
#Modeline "1152x882" 121.5 1152 1216 1344 1576 882 883 886 925 +hsync +vsync
#Modeline "1152x864" 185.0 1152 1216 1440 1664 864 865 868 911 +hsync +vsync
EndSection
Section "Device"
Identifier "NV AGP"
Driver "nvidia"
VendorName "Videocard vendor"
BoardName "NVIDIA GeForce 4 (generic)"
VideoRam 131072
Option "TwinVIew" "1"
#Option "IgnoreEDID" "1"
Option "RenderAccel" "1"
Option "NvAGP" "3"
Option "DigitalVibrance" "16"
Option "NoLogo"
Option "CursorShadow" "true"
Option "CursorShadowXOffset" "5"
Option "CursorShadowYOffset" "4"
Option "SecondMonitorHorizSync" "30.0-85.0"
Option "SecondMonitorVertRefresh" "50.0-160.0"
Option "ConnectedMonitor" "CRT,CRT"
Option "MetaModes" "1152x864, 1152x864; NULL, 1024x768;"
#Option "MetaModes" "1152x864, 1152x864; 1152x864, NULL; NULL, 1152x864; 1024x768, NULL"
#Option "UseEdidFreqs" "1"
Option "Xinerama" "0"
Option "TwinViewOrientation" "LeftOf"
EndSection
Section "Screen"
Identifier "Screen0"
Device "NV AGP"
Monitor "Monitor0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1024x768" "800x600" "640x480"
EndSubSection
EndSection
Section "DRI"
Group 0
Mode 0666
EndSection
