To answer a previous question on this thread,
For people whose hard drive fails after they've been "married" on XBL, then when the HD is replaced, replace the EEPROM also. Then, use XBL's Account Recovery to re-install your gamertag (this makes XBL think you bought a new console) and you're re-married with the new HD and EEPROM. If you don't use Account Recovery, then when you try to sign on, the new serials won't match the ones on record, and you're new stuff will get banned, so you'll have to go through all of that again.