I have a Macbook running OS X Leopard. Occasionally within a few minutes after booting, both Dock and Finder will crash. If they don't crash soon after boot, the computer seems to run fine for quite a while. I've tried a repair permissions, but the results were inconclusive at best: the next few boots were fine, but then it started crashing again. Does anyone have any diagnostic suggestions or possible resolutions?
Check the Console logs, they may have some clues that could help this. Permissions repair's effectiveness in general is questionable, but you should verify the filesystem integrity as well to be sure.
If you can't get anything from the console log and don't have any other suggested options, you could always reformat, reinstall, and then migrate your user account.