Keyboard stop working when mining underwater

I just dowloaded the new map ''Ant Farm'' from the store. When playing in, if I try to mine underwater, my whole keyboard stop working. Whatever I click doesn't respond unless I leave my finger on it for a whole minute, one letter at a time. I then have to restart my computer for it to go back to normal. It doesn't happen with any other maps, and I generally never have problems with minecraft or my computer.