I'm getting this, even with FireFox 3.5, the x-org Edgers updates, and the latest 2.6.30.3 kernel from the mainline Ubuntu repo.
Otherwise 9.04 with KDE 4.3 latest RC from the Kubuntu repos.
Intel GM965 hardware (hence the funny kernel and X to unbreak them from what 9.04 shipped with).
I'm getting this, even with FireFox 3.5, the x-org Edgers updates, and the latest 2.6.30.3 kernel from the mainline Ubuntu repo.
Otherwise 9.04 with KDE 4.3 latest RC from the Kubuntu repos.
Intel GM965 hardware (hence the funny kernel and X to unbreak them from what 9.04 shipped with).
I will try getting a trace.