After upgrading to Ubuntu 11.10, MythTV started having issues. During playback purple/pink bars were displaying across the screen (for example) and the fix/workaround was pretty simple: change from CPU+ to Slim in Setup->TV Settings->Playback. However, this isn't the only problem I've been experiencing since the upgrade. It's not clear at this point if the problems are specific to MythTV or the ATI/AMD video drivers, but there are issues running MythTV on this combination of OS and driver right now.