Would anyone be willing to test with the latest pre-release of Jaunty 9.04 (currently Alpha4). It contains a newer 2.6.28 based kernel. It would be great to know if this issue remains. Also note that Jaunty Alpha5 is expected to come out within the next few days so you may want to test with this even newer Alpha - http://cdimage.ubuntu.com/releases/jaunty/ . Please let us know your results. I'm also reassigning this to the ubuntu-kernel-team. Thanks.