I did some more fiddling and I'm fairly well convinced that this is actually a 'gnome-screensaver' bug.
I first booted into an Lubuntu Precise and installed 'gnome-desktop- environment' which I know is Gnome version 3.0 rather than the Gnome version 3.2 + bits of 3.4 that Ubuntu Precise uses. Booting into a "gnome classic (no effects)" session uses 'gnome-screensaver' and results in this bug, but booting into an Lubuntu session which uses 'xscreensaver' works just fine. In the meanwhile the last bits of the new Xorg stack fell into place in Ubuntu Quantal proposed so I applied those updates, but no joy :^( Next I decided to try converting an Ubuntu Precise from using 'gnome- screensaver' to using 'xscreensaver'. It was a bit fiddly for me. I first tried this: http://www.howtogeek.com/114027/how-to-add-screensavers-to-ubuntu-12.04/ But that didn't quite work properly on reboot so I deleted the new entry in Startup Apps and tried this: http://www.liberiangeek.net/2012/04/add-enable-screensavers-in- ubuntu-12-04-precise-pangolin/ Sadly 'xscreensaver' was still NOT working properly on reboot so I opened Startup Apps again, noticed Xsreensaver was once again added, so removed and re-added it. No idea why but it then worked OK on repeated reboots. So that's just fiddly enough I can't recommend it as a work-around!!!! Regardless, once I had 'xscreensaver' working properly with the "blank- screen" option in Ubuntu Precise, I tried this with my KVM switch and all was well. So I'm fairly well convinced this is a 'gnome-screensaver' bug. The next step is to see if we can find something upstream (or side- stream in another Gnome based distro) so please help me search :^) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/988290 Title: Resolution change with KVM switch on Precise To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/988290/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs