Ive been trying to get dual monitors to work in X now for a couple days. Actually it does "work", but pretty poorly. The window manager locks up often for a few seconds, and then many times the screen other than the one I am working on will pop up little "remnants" of buttons, text, etc. randomly placed. Heres the details:

Primary card: Voodoo3 PCI
Secondary card: Voodoo3 AGP
XFree86 v. 4.3.0

I have tried this with xinerama extensions both on and off. The modelines for my monitors have both been commented out because I cant get the resolutions right when I use them. Anyways, I know I hate it when people post their entire XF86Config file, but I'm gonna do it anyways.

Section "ServerLayout"
Identifier "XFree86 Configured"
Screen 0 "Screen0" 0 0
Screen 1 "Screen1" RightOf "Screen0"
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/local/"
FontPath "/usr/X11R6/lib/X11/fonts/misc/"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled"
FontPath "/usr/X11R6/lib/X11/fonts/Type1/"
FontPath "/usr/X11R6/lib/X11/fonts/CID/"
FontPath "/usr/X11R6/lib/X11/fonts/Speedo/"
FontPath "/usr/X11R6/lib/X11/fonts/75dpi/"
FontPath "/usr/X11R6/lib/X11/fonts/100dpi/"
FontPath "/usr/X11R6/lib/X11/fonts/cyrillic/"
EndSection

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

SubSection "extmod"
Option "omit xfree86-dga"
EndSubSection

EndSection

Section "ServerFlags"
Option "Xinerama" "true"
EndSection

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

Section "InputDevice"
Identifier "Mouse0"
Driver "mouse"
Option "Protocol" "ExplorerPS/2"
Option "Device" "/dev/mouse"
Option "Emulate3Buttons" "no"
Option "Buttons" "5"
Option "ZAxisMapping" "4 5"
EndSection

Section "Monitor"
Identifier "Monitor0"
vendorname "Hewlett-Packard"
modelname "HP Ergo 1280"

HorizSync 31-92
VertRefresh 60-150

#ModeLine "1280x1024/85Hz" 157.5 1280 1344 1504 1728 1024 1025 1028 1072 +HSync +VSync

EndSection

Section "Monitor"
Identifier "Monitor1"
VendorName "CyberVision"
ModelName "C72"

HorizSync 30-70
VertRefresh 50-120

#ModeLine "1152x864" 106.91 1152 1200 1440 1536 864 866 878 904 #77Hz

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 "NoAccel" # [<bool>]
#Option "SWcursor" # [<bool>]
#Option "UsePIO" # [<bool>]
#Option "ShowCache" # [<bool>]
#Option "VideoKey" # <i>
#Option "NoSLI" # [<bool>]
#Option "TexturedVideo" # [<bool>]
#Option "DRI" # [<bool>]
Identifier "Card0"
Driver "tdfx"
VendorName "3Dfx Interactive, Inc."
BoardName "Voodoo 3"
VideoRam 16384
BusID "PCI:0:9:0"
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 "NoAccel" # [<bool>]
#Option "SWcursor" # [<bool>]
#Option "UsePIO" # [<bool>]
#Option "ShowCache" # [<bool>]
#Option "VideoKey" # <i>
#Option "NoSLI" # [<bool>]
#Option "TexturedVideo" # [<bool>]
#Option "DRI" # [<bool>]
Identifier "Card1"
Driver "tdfx"
VendorName "3Dfx Interactive, Inc."
BoardName "Voodoo 3"
VideoRam 16384
BusID "PCI:1:0:0"
EndSection

Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "Monitor0"
DefaultDepth 24

SubSection "Display"
Depth 24
Modes "1152x864"
EndSubSection
EndSection

Section "Screen"
Identifier "Screen1"
Device "Card1"
Monitor "Monitor1"
DefaultDepth 24

SubSection "Display"
Depth 24
Modes "1152x864"
EndSubSection
EndSection

anyone?