X-Server problems in Ubuntu 10.04 release candidate
The release candidate of Ubuntu 10.04 published on Thursday, apparently contains a bug in X-Server. A Launchpad bug report, [KMS] gem objects not deallocated, describes the details. The bug makes itself felt as a slowly growing memory hole in X-Server. After a few hours of operation, so much memory is taken up that X11 becomes noticeably slower and eventually the computer is no longer operable.
The developers have already made a bug fix available, though not yet to all installations; they first want to test whether the bug fix has any side effects. A wiki site describes how the problem can be diagnosed and the bug fix installed. The wiki also shows collected feedback on the problem.