I took the battery pack out of the TK35, charged the batteries, and put it back in. Only I may have put it back incorrectly, because now the light goes on when I screw the head back on, and the buttons at the back appear pushed out, and don't work. So I guess if you're not careful you can put the battery pack back in the light incorrectly? Does anybody have any idea how to get it out? It appears to be stuck. Thanks for any suggestions.