Try the Option "MonitorLayout" "LVDS,AUTO" thing mentioned before in this thread. Add it to the device section in your /etc/X11/xorg.conf
That worked for me and my mobility radeon X700. -- [x700] fails to infer lvds for primary connector on acer ferrari 4005 | card detected, but driver fails to use right output port https://launchpad.net/bugs/22985 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
