Ok my scenario so far......my xbox was banned...
I brought my HDD to my cousins xbox (not modded) And it worked fine. Not only my game saves where working but it logged into live also. I then copied my gamesave and profile to my cousins memory card and then I removed my HDD and put my cousins back. We played Borderlands (retail on his non modded xbox) fine. When done I put back my HDD (we did this since my cousins HDD had his stuff on it so thats why I was doing all this switching) and I copied my game save and gamertag back to my HDD. Went home to my banned xbox and all is good.
HOWEVER, my cousin came by me and had his profile and his gamesave on his memory card and we played Borderlands on my banned xbox. He played off of his memorycard and didnt do any copying or moving whatsoever to my HDD. When he returned home to his non modded xbox and tried to put back his gamertag and game save on his HDD it was all corrupt. But MY stuff seems to be ok still.
Things ive noticed with my HDD:
1. Can no longer copy games to my hard drive (pretty much everyones noticed this by now)
2. If I already had a game installed on my HDD b4 the ban, I cannot play it off the hdd. gives this msg "This game can only be played on the console and hard drive it was originally installed on. To play on this console, delete and reinstall the game." Tried with all the games that where installed, same msg.
3. Still loads my game saves and saves my games when playing on my banned box.
4. Im guessing (going by what happened to my cousin) M$ allows you to bring your stuff to another xbox however someone elses profile from another xbox cannot be brought to the banned box because once removed it gets currupted. Just a thought im no expert....