Okay, this is annoying.

I'm running Ubuntu 12.04 LTS. The box it's installed on uses onboard Intel video, and I normally use XFCE4 as my desktop.

I have a 27" AOC monitor that uses 1920x1080 as the standard resolution. It was a replacement for a failed Viewsonic, and I was delighted when I attached it and Ubuntu detected the resolution and used it.

It worked fine until half an hour ago, when Update Manager informed me there were updates and I installed them. One broke screen resolution: Ubuntu now refuses to admit the monitor will do more than 1024x768.

I recall having this issue before on another machine that did 1280x768 native, and a Ubuntu 11 series update reduced it to 1024x768. I never was able to track down what the problem was - poking around in system logs showed that Ubuntu knew the hardware could do the higher resolution, but nothing I did from the desktop would make it do so. The problem got resolved in a subsequent release.

Is there a known fix for this? Upgrading to 12.10 is not currently an option.

Thanks in advance.