I have very similar bug, see bug 37236 .
I must insert in monitor section this line:
Option "MonitorLayout" "LVDS,AUTO" .
I have a Ati Mobility Radeon X700 and a display 15" widescreen 1680x1050 .
If I install fglrx driver (or use vesa driver in xorg.org) and reconfigure X without the line Option "MonitorLayout" "LVDS,AUTO", the display run but not at the optimal resolution and with lose performances.
I have very similar bug, see bug 37236 .
I must insert in monitor section this line:
Option "MonitorLayout" "LVDS,AUTO" .
I have a Ati Mobility Radeon X700 and a display 15" widescreen 1680x1050 .
If I install fglrx driver (or use vesa driver in xorg.org) and reconfigure X without the line Option "MonitorLayout" "LVDS,AUTO", the display run but not at the optimal resolution and with lose performances.
Regards,
gp