There have been a few bugs in 3.8 recently, it looks like some of those might be affecting you.
Can you try the v3.9-rc3 mainline kernel? http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.9-rc3-raring/ ** Changed in: xserver-xorg-video-nouveau (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1114431 Title: screen goes stand-by if i choose 1280x1024 resolution To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1114431/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs