Comment 47 for bug 749817

2011-04-21 11:24:54 configure xserver-xorg-video-intel 2:2.14.0-4ubuntu8~lp747205~2 <none>
2011-04-21 11:24:54 status unpacked xserver-xorg-video-intel 2:2.14.0-4ubuntu8~lp747205~2
2011-04-21 11:24:54 status half-configured xserver-xorg-video-intel 2:2.14.0-4ubuntu8~lp747205~2
2011-04-21 11:24:54 status installed xserver-xorg-video-intel 2:2.14.0-4ubuntu8~lp747205~2
2011-04-21 11:24:54 status triggers-pending libc-bin 2.13-0ubuntu13
2011-04-21 11:24:54 trigproc libc-bin 2.13-0ubuntu13 <none>
2011-04-21 11:24:54 status half-configured libc-bin 2.13-0ubuntu13
2011-04-21 11:24:55 status installed libc-bin 2.13-0ubuntu13

With just your xorg ppa packages installed, I get one of the variants of misbehaviour previously encountered, specifically:

at the gdm prompt, internal only
after logging in (to classic): blank on both
after pressing fn-f7, internal-only works, joined works, mirrored works, but external-only is black on both

When I had this before it was not stable and sometimes would get stuck with no monitors, or show the flashing display.

I will try the intel kernel next.