Xbox 360 "corrupted profile" question
 

Ok so I have got a 360 that was purchase in the first wave, and its been working fine, untill just recently. I purchased oblivion, and I popped it in, and waited, and waited, and it never loaded. thought I might have a bad copy, so I exchanged it, only to find out the next copy did not work. So I did some troubleshooting, and what I think is happening, is whenever a game tries to access the hard drive through the game (I can play all the demos and listen to music thats on the hard drive), it freaks out and corrupts my profile. So when I go back to the dashboard it no longer has my info on my profile. I turn off the console and back on and things are fine. I play Amped on it without any problems whatsoever. so I dunno what the deal is. I have tried reformatting the hard drive, and that has not worked. So my question is, has anyone heard of this happening? are there any fixes? did I do something to cause this? any help would be great, thanks!