I dont find Repairing permissions to be a cure-all, it hasn't really solved any of my problems.
I've found that i get strange finder quits/restarts when working on a network server with image previews turned on in icon mode, as soon as i open the window the Finder quits and restarts every time i open the window until i turn off image previews, then it appears to function normally, the problem does not occur however when i am in column mode and working in the same server.
The problem occurs whether or not i am using Airport, or Ethernet, and whether or not it's a big file or a small file, however it has only done this with image files, no other files seem to trigger this rash of quits/restarts.
-Telusman