With the development profile I had the same problem. But I found my error.
I have a explicit app id for the store (testflight). The inapp purchases are added for this appid.
For testing I used another explicit id, which was a result of the a wild card app id.
The problem for me starts with :
- App Id - Create wildcard app id
I think for beginners its better to create an explicit app ID for each app they develop.
Than create different profilestring and certificates for different purposes for this explicit app id.
- store
-developement
- adhoc ....
But this is only my opnion.
But thanks all for helping always.