Running 64-bit Ubuntu 10.04 on identical hardware as well. However, I've had the laptop hooked up to my TV now (via VGA cable) for several hours with "mirror screens" and haven't had the problem at all - the TV does not support 1366x768, so both screens are now set to 1360x768 instead. Nothing else has changed - compiz is still running. I also briefly tested dual monitor mode with the laptop display @ 1366x768/60Hz and TV @ 1360x768 - had browser & terminal windows open on both, and did not notice any flickering.
A quick search online showed a user with a Dell 1545 w/ Intel GM45 integrated gfx was having similar problems using Fedora 12's Intel xorg driver - http://bugzilla.redhat.com/show_bug.cgi?id=519734 . Several other distros showed up w/ similar problems with laptops w/ Intel GM45 GPUs. They also seem to confirm adding "i915powersave=0" to the cmd line in Grub seemed to solve the problem. Just as that command line configuration seems to work for a lot of people, I wonder if adding the 2nd display stops the flickering for me because it causes power-saving mode for the GPU to be disabled? I have no idea. Don't recall whether or not I had the problem with Karmic - I bought the laptop in January & installed 9.10 but I upgraded to Lucid Alpha 3 in February. The flickering hasn't been frequent enough to become much of a distraction for me. No problem doing anything graphics-intensive - I can play videos online w/ 64-bit Flash Alpha & I can even watch Netflix movies in a full-screen WinXP box w/ VMWare Player. I can even rotate compiz cylinder while its running and see the video playing behind my other desktops. The flickering definitely seems to have something to do with the power mgmt. modes on the GPU. In fact, I seem to notice flickering MOST significantly when using a terminal window (terminal w/ ambiance theme w/ transparency, if that helps any). Yesterday, I had to run e2fsck so I put in a Linux Mint 9 live CD (which I assume uses the same Intel drivers?) & opened a terminal and the same problem occurred. I'll try turning powersave off for a few days and see how it works and what kind of impact that has on the battery life & temperature. Not a significant problem for me though, but anything I can do to help w/ testing, let me know. This is my first posting on here so sorry if I missed some of the board rules! Dave ** Bug watch added: Red Hat Bugzilla #519734 https://bugzilla.redhat.com/show_bug.cgi?id=519734 -- random flickers on ubuntu lucid desktop https://bugs.launchpad.net/bugs/574449 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs