Today I turned on my Xbox for the first time in a week or so today, and it was bugging out, rebooting itself as soon as I got logged into Xbox Live.
I tried unplugging the ethernet cable from the Xbox, and I'm able to play any game offline, watch downloaded videos, etc.
When I plugged the cable back in and tried to sign in again, same deal.
After a quick google search, I came across this thread: http://forums.xbox.com/xbox_forums/xbox_support/f/7/p/35912/229044.aspx and decided to check my downloads. I then realized that the last thing I'd done was watch episode 6 of the latest season of The Guild (Revolving Doors), and had chosen to download it after watching it. I went into my video library, found the partially downloaded episode, and deleted it. I then plugged in the ethernet cable once again, signed into Xbox Live, and voila! Problem solved!
Wanting to be scientific about it, I decided to see if I could figure this out. I hopped into the game marketplace, and downloaded a trailer for Gears of War 3. No problems detected, download completed. I then went back to the Zune Video marketplace and tried to download the same episode of The Guild again. Once I hit the "download" button, it rebooted, and continued on the same reboot cycle until I unplugged the ethernet cable, deleted the file, and re-signed in to Xbox Live.
So I now want to know if that episode is just a corrupted file, or if I am now forced to have a hole in my collection of The Guild videos on my harddrive from now until the end of eternity?