Weird problem - nasty Finder bug?

I'm having a weird problem with the Finder in Lion. Every now and again it will (randomly) stop being able to list the contents of folders and disk images. Only a reboot seems to be able to fix it.

When I open a folder or disk image, I just get the small spinning wheel in the bottom right of the Finder window and it never manages to lists its contents (even if there is only 1 file in there). If I have already opened the folder previously before the problem occurs, it is able to display the contents of that folder with no problem.

Even more strangely, if I do a get info it knows there are items in there (in most cases) but can't display them in the window.

Terminal can see the files with no problem.

Its happened a few times in 10.7, 10.7.1 and today in 10.7.2 - There doesn't seem to be anything in Console, and if I try to sample the kextcache process in Activity Monitor it never finishes.

Any ideas how this could be tracked down for the Apple bug reporter?