explorer.exe running twice

I have a problem with winxp32 SP2.

Even after a re-install, two copies of explorer.exe show up in task manager. They are both lowercase, neither is "Explorer.exe".

I only have one explorer.exe on the hard drive.

When I close them: One seems to be handling the folders that are open & the other seems to be running the start menu, clock, etc...

I wouldn't even mind the waisted memory, but after a while I start to have a big problem that can only be fixed by closing both & re-starting explorer.exe. After I re-start explorer, it happens again after about 10 minutes.

The problem is that it will only let me open like 4 folders, then won't let me open any more (or if they do open, there is nothing in the menu & the bar with "file, edit, view..." just has a windows logo, no words.

I can't seem to find any information on this problem, only on ones involving Explorer.exe.

I tried re-installing from a clean, pressed, orriginal microsoft cd, used a clean, pressed MS sp2 upgrade, and used windows update to bring it up to current, it still does it!

Any ideas?