(PS3 and xbox360) Tomb radier underworld: i have got thors belt but it's not letting me move the rock!!! >:(?

Cant open door to proceed to next level. Got belt and key. PS3 crashed during game. Lara tells me i can move on but when i leave the room she says i need the key i already picked up again. Weird! Any cheats to skip level? I cant restart the level as it's already been saved at a certain checkpoint and the thors belt is not working even thou i have picked it up and there is nothing i can do to exit the place have i got to start all over from level 1? >:( ****** **** glitchy game!!