I am having problems testing my in-app purchases. I get back valid product identifiers, but upon purchase I receive the dreaded \"Cannot connect to iTunes Store\". Interesti
I've been having this problem and I'm convinced its a bug. I've filed a bug report with Bug Id 10108270
The problem seems to be that the test user is getting 'locked' and may have something to do with attempting to purchase an in app purchase in an already released app with that account.
My workaround was to create a new test user but until Apple get back to me, I can't provide any better solutions. I'll update this answer when I get replies.