Ya for me i have to single click for it to work, when i firsted started boxing this problem would plague me for minutes as i stood there. I would keep having to open and close the flight screen till i flew away. Then i googled it and read it was some bug... cant believe it still aint fixed though... been a while. Kinda irritating for me cuz i love button mashing! LOL its hard to be calm and single click and wait as your about to die... (pvp server) haha