I am using Fedora 6 system,onbaord display controller intel 82825/855 chipset(vga+dvi),and using Eizo L365 (dvi),viewsonic VE510(vga) monitor.
By default,when i power on system,both monitor runing clone mode display,but when i enable dual head function on system (spanning screen),system crash can't go in x window when after reboot system,
how can i using spanning screen on my system(or change other linux os)?Thx any linux master for help

single mode display xconf file:
# Xorg configuration created by system-config-display


Section "ServerLayout"

Identifier "single head configuration"

Screen 0 "Screen0" 0 0

InputDevice "Keyboard0" "CoreKeyboard"

EndSection


Section "InputDevice"

Identifier "Keyboard0"

Driver "kbd"

Option "XkbModel" "pc105"

Option "XkbLayout" "us"

EndSection



Section "Device"

Identifier "Videocard0"

Driver "i810"

EndSection



Section "Screen"

Identifier "Screen0"

Device "Videocard0"

DefaultDepth 16

SubSection "Display"

Viewport 0 0
Depth 24

EndSubSection

SubSection "Display"

Viewport 0 0
Depth 16

EndSubSection

EndSection






enable dual head xconf:
# Xorg configuration created by system-config-display


Section "ServerLayout"

Identifier "Multihead layout"

Screen 0 "Screen0" LeftOf "Screen1"

Screen 1 "Screen1" 0 0

InputDevice "Keyboard0" "CoreKeyboard"

Option "Xinerama" "on"

Option "Clone" "off"

EndSection



Section "InputDevice"

Identifier "Keyboard0"

Driver "kbd"

Option "XkbModel" "pc105"

Option "XkbLayout" "us"

EndSection



Section "Monitor"

Identifier "Monitor1"

VendorName "Monitor Vendor"

ModelName "ViewSonic VE510+"

### Comment all HorizSync and VertSync values to use DDC:

HorizSync 30.0 - 62.0

VertRefresh 50.0 - 75.0

Option "dpms"

EndSection



Section "Device"

Identifier "Videocard0"

Driver "i810"

EndSection



Section "Device"

Identifier "Videocard1"

Driver "i810"

VendorName "Videocard Vendor"

BoardName "Intel Corporation 82852/855GM Integrated Graphics Device"

BusID "PCI:0:2:0"

Screen 1

EndSection



Section "Screen"

Identifier "Screen0"

Device "Videocard0"

DefaultDepth 16

SubSection "Display"

Viewport 0 0

Depth 24

EndSubSection


SubSection "Display"

Viewport 0 0

Depth 16

EndSubSection

EndSection



Section "Screen"

Identifier "Screen1"

Device "Videocard1"

Monitor "Monitor1"
DefaultDepth 16

SubSection "Display"

Viewport 0 0

Depth 16

Modes "1024x768"

EndSubSection

EndSection

"Several different multi-monitor options are supported by the Intel 852GM chipset family. The availability of each of these options is dependent upon the specific motherboard implementation"

From intel's site about that chipset.

Try twin view and not extended. Also, which driver are you using?