Getting out of Parallels stuck windows key bug

Parallels has an annoying habit (ok bug), of not releasing certain keys at times. Start to type and hit "r" and the run prompt will appear. Type "e" and explorer will spawn another window *grrr*.

The remedy? Press cmd-option-enter. Parallels will ask you if you wish to enter full screen mode. Say no and you will magically have fixed the stuck windows key. Rubbish that this has to happen, but at least it fixes it until the Parallels team do ;)