Has anyone else experienced a video issue when upgrading to Ubuntu 11.04?
Also remember you can pull up the Nvidia Settings panel by launching it from a terminal like so: gksudo nvidia-settings
If you have trouble saving the changes to X hit the "Preview" button to bring up the file, copy and paste the text into another editor. Then do a sudo gedit /etc/X11/xorg.conf to open up the file with SU permissions and paste the update info into Xorg.
When the performance started to get extremely flaky (inability to maintain display settings, window redraw problems, glitchy video playback, freezing), I upgraded to 11.04 in hopes that my problem was somehow attributed to a setting I may have inadvertently changed. Not so.
Somewhere along the line, the NVIDIA driver supplied in Ubuntu ceased to function, and I seem to remember that a number of people have a similar problem. Once I discovered this was the case, I (being short on time) gave up and stripped the desktop of any eye candy and new functionality by using the Gnome Classic setting. Video playback and screen redraw can be problematic still, but the desktop (barely) functions.
I don't have the links to my original findings, but my recommendation is to scour Ubuntu Forums. You may just find people with your exact problem, and maybe even a solution or explanation.
Every time in the past that I have told myself upgrading to a later Ubuntu might make video performance, I have generally found the opposite to be the case. I'm becoming more inclined to just live with whatever version I have indefinitely once I have everything working as expected with the video hardware. If something becomes a problem, then I upgrade. It has become enough of a problem that I am seriously contemplating a move to Debian, where things stay more stable thanks to not getting new features as quickly.
Cannonical Ubuntu (stupid link, yes I know)