I would like to make it clear on whats involved to UNban your 360.First of all, you need to either have 4532 or downgrade to it.You also need to run a modified backup of King Kong(which requires modified FW which requires your DVDkey)You also need to run linux via serial, or the linux gentoo beta 2 CD.Once linux is booted, you need to run a program on your 360 called dump32 to get your FUSES.txt and 1BL.bin. Now your 360 can be Unbanned.....BUT....you need to do this all over again to a different 360 that hasnt been banned.
So lets think of a few reasons to go through all this trouble:
1. You got a really good deal on non banned 360 with or without a drive, but has the DVDkey, that overheats after running a few hours (enough time to perform this task).
2. your just crazy and want to say you did it.
3. I really cant see any other reason other then the two above and i cant see anyone selling a 360 with the DVDkey for really cheap unless its RRod or in a best case senerio it just overheats after a few hours of play, and is bound to RRod in the immediate future.
In my case, I had a launch day 360 the would freeze/lockup with green checker blocks within 5 minute of running, I tried every cooling mod to date, short of reballing the gpu, or water cooling, and i found that running it directly over an AC would keep it cool enough to run for an hour or so, just enough time to downgrade it, and get the FUSES.txt, and 1BL.bin that contained the CPUkey.So even though this 360 is pretty much useless, I feel good i accomplished something, and if i ever need an extra CPUkey i have one.