Sorry, Martins, I thought I had replied to this already, but appearently not.... Instead of closing Explorer, navigate to another drive - your CD / DVD (provided there is a disc in) or else to a local HD.... Another thing, is it possible that your AV is scanning the drive prior ot releasing it (old scanners, particularly Norton / Symantec, used to watch for removable media and scan them on removing, so it was just a thought). If changing the explorer window to another drive does not alleviate the symptoms, and it is not your AV program, do you have ReadyBoost enabled? That could partially be part of the problem as well, if it is actively using it....