Help please!!

I'm in Las Vagas at the mo n I've just picked up the room key for level 9 but when i go to the elevator it doesnt give me the option to go to level 9 :s and when i look in my inventory its not there either...

I've already tried going back to the room, but the chest has been opened.. I've also tried restarting the game.. Nothing seems to work.. What do I do?

If anyone knows how i can overcome this or has had this problem too, please write back with advice on how to overcome this.. I'm stuck unless i can solve this problem

Lockheart88