USB flash drive works only after reboot

Hi.

I have a problem with USB memory stick and Windows XP (SP2).

When I plug in the memory stick, Windows recognises it and even assigns a
drive letter for it. But when I try to access the flash drive I receive an
error message: "I:\ is not accessible. Incorrect function.". After rebooting
Windows I can access the flash drive normally and everything works fine.

I don't know if this gives any clues but I have noticed that before reboot
the flash drive is titled as "Local Disk" and after reboot when the drive is
working properly it is titled as "FLASHDRIVE".

At first the memory stick was working fine and it still works without any
problems in my laptop. I can't remember doing anything special at the time
when I started to notice this problem. It might have started after I plugged
in my friends USB memory stick which didn't work in my computer for some
reason.

I have tried to uninstall all USB devices on Device Manager and let Windows
to reinstall them on the next boot, but that didn't help.

Any other ideas?