All right, guys, after a month of having this problem kick my butt all over the internet, I've figured it out. First my problem: whenever I tried to watch movies that i had rented/purchased from the android market, the video app on my GT10.1 would tell me that I had a network problem and would not let me watch or download anything. I checked the apps, I checked my network, and I put tickets in with Google. Nothing. I use a Google Apps account as my primary google account on all of my devices and this proved to be the problem. I had never activated the You Tube service on my Google Apps domain admin sight and thus never "activated" my you tube account. Once I did that, signed in to You Tube, everything works excellent!
Hope this helps anyone else out there having this issue.