Mouse sticks only when dropping with drag and drop. I'm having a problem with dragging and dropping on my Mac. The icon is picked up, but it doesn't let go most of the time; it's almost as though I've still got the button down.

Please note: this only happens with dragging and dropping, not with highlighting text. When I do that, the trackpad releases as you would expect. If it didn't, I'd suspect a hardware error but it just works perfectly for everything else (highlighting text, playing games etc).

What can I do to fix this?
I had a similar problem and solved it by relaunching the Finder (Force Quit).