stefanp - the leaderboard thing should be fixed, same for payments - let me know if they both work for you. If you're curious about the payments issue, the response Paypal sends back isn't completely standardized, so it wasn't sending back everything in the same format that it usually does, so I had to account for that.
I finally upgraded to iOS6 and tried out the close icon, and it works. I'm guessing it's some sort of conflict with Construct 2, can you send me the link for you game so I can try it out?
I did make one change that *might* fix it, so do try once more and let me know.