I had the same problem with the 0x457 update on my HR21-100. TVApps used to work just fine--when they actually worked--but now all I get is the 301 error. I have tried hard resetting the HR21, my router, first putting the settings on AUTO, then manually configuring the STB ports, port forwarding ports 27177 and 27178, putting the HR21 in the DMZ in my router, etc. Nothing has worked. If it is my router--and I'm betting it is not--it is not worth replacing it just to get friggin' "TVApps" working. There were nice to have, but not vital. Still, lots of users are having issues with this, and DirecTV has been both flippant and fairly useless coming up with a solution.