Can't delete files, folders or create folders with explorer

I have had this problem off and on for about a year. Sometimes my XP SP2
Dell 8400 machine, using explorer will be unable to delete a file or create a
folder(subdirectory). If I do the same function using dos commands it works
fine. Explorer will lock up and have to be canceled. If I reboot that
temporally resolves the problem. I was told once that this could be due to
too many files in my temp directories so I clean them up on a regular basis,
so I don't think that could be the problem. Any help would be great as it is
very inconvient to have to reboot everytime this happens.

--
Macon
XP-Pro SP2
WMP10
Office XP