Mouseferatu said:5 minutes rest required, no matter what. If you have a second encounter after 3 minutes, for instance, you don't get the benefits of the short rest, and you're still out of any encounter powers you used in the prior fight.
Ah well I think I got a house rule then. 5 minutes is a long time, i can accept it as some kind of balance on abuse of abilities outside of encounters, but really you are in a dungeon how often does it take 5 minutes for other parts of the dungeon to respond. They are not the police responding form 10 miles away after they get a call, there two rooms away wondering what all the screaming was about.