Currently Being ModeratedAug 29, 2013 8:40 AM (in response to Bryan B.)
Thank you for the details of the issue you are experiencing with the iTunes Store. You have tried some really good troubleshooting steps already, but I found a couple of articles with some additional steps that address an issue like this.
I recommend reviewing the following articles (you can skip any steps you have already taken):
Thank you for using Apple Support Communities.