Oddly the same here. Actually I am have a few little problems. I am gonna re-boot and clear caches, repair disk/permissions.
The mouse gets jerky. As if the CPU is maxing out but there are not processes that are. Its annoying. This used to happen to me in 10.5.0 when Time Machine is doing a back-up and my external iSight is connected.
After installing the OS X 10.5.1 update, I ran into a weird glitch where the scroll button would only go down, but not up. I rebooted, and everything seems to be back to normal.