This is my issue.  Several apps do have permissions (shown in the charms bar as having permission to use the internet for example) such as Microsoft Software Collection, Taptiles, Mahjong, Xbox video, Pinball FX2 etc etc. However not a single one shows up as an app or service that has permissions when I check my online (MSN Premium) account. I either can't sign into XBox for Solitaire or, I can't make a purchase in Xbox video or sign into Xbox Music. I've tried just about every fix short of a clean install. Since it appears to be some sort of issue with permissions, I doubt that would work.