I have this two-monitor configuration that works flawlessly in the default 12.10 GNOME wm. This is my xorg.conf:
Section "Monitor"
Identifier "VGA0"
Option "Enable" "true"
Modeline "1920x1200_60.00" 193.16 1920 2048 2256 2592 1200 1201 1204 1242 -HSync +Vsync
Option "PreferredMode" "1920x1200_60.00"
EndSection
Section "Monitor"
Identifier "LVDS0"
Option "Enable" "true"
Modeline "1368x768_60.00" 85.86 1368 1440 1584 1800 768 769 772 795 -HSync +Vsync
Option "PrefferedMode" "1368x768_60.00"
EndSection
Section "Device"
Identifier "Radeon0"
Driver "radeon"
Screen 0
EndSection
Section "Device"
Identifier "Radeon1"
Driver "radeon"
Screen 1
EndSection
Section "Screen"
Identifier "Big Screen"
Device "Radeon0"
Monitor "VGA0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1920x1200"
EndSubSection
EndSection
Section "Screen"
Identifier "Little Screen"
Device "Radeon1"
Monitor "LVDS0"
DefaultDepth 24
SubSection "Display"
Depth 24
Modes "1368x768"
EndSubSection
EndSection
Section "ServerLayout"
Identifier "My Layout"
Screen 0 "Big Screen"
Screen 1 "Little Screen" RightOf "Big Screen"
Option "Xinerama" "true"
EndSection
However, awesome wm that I am trying to set up right now is simply mirroring upper left part of the bigger screen to the smaller screen. Although I am happy that the resolution is right, I would obviously like to fill each screen with different content.
What am I doing wrong?