Another issue that seems to be somewhat common is the inability to eject media, such as CF cards or external FW drives, some of the time.
The OS claims it is busy and recommends quitting applications. Quitting applications doesn't seem to help, the only way to eject the affected media is to log out and back in.
It doesn't happen all the time, and I'm unsure what action triggers the problem. I do know that if I access my LR library which is on the external FW drive, I will not be able to eject that drive.
This seems to be a pretty common problem, quite a few discussions about it.