Coco2d OnEnter Crash Problem

I was sent a project to work on and it immediately crashed when I tried to run it in the iphone simulator. I tracked down the spot where it crashed and it happened in the CCDirector.m setNextScene function when it calls onEnter on the runningScene. I stepped through the code and it when through the entire onEnter function in CCNode.m. When it got to the end of the function, I went to step out of the function and it jump back to the beginning of the OnEnter function and started to run it again. It then crashed with a EXC_BAD_ACCESS error when it called onEnter on its children. I asked the person who sent me the project and he say it might be a sync issue. He had never had this problem when he ran it on the iphone but he never tested it on the simulator. Would anyone have any ideas what the problem is and how to fix it? Thanks.