IAD Test ads dont work in 4.2 or 4.3 on device or simulator

I cant seem to make the test a开发者_StackOverflow中文版ds work for anything other than 4.1 or 4.0 in the simulator. I downloaded the iAdSuite sample code from apple, and still can't get it to work under 4.3/4.2. I don't think the problem is with my code. could there be anything else that could cause this error?

---

a) if you have questions whether your code is wrong...you should post your code

b) have you looked at the responses your iAd delegate is receiving? often times I receive 'no inventory available' even for test ads.