Funnily enough, mine started random freezing in November. No red rings, just total lock up. It did it pretty consistently within 5 minutes of launch, so after relaunching three times, I called to get it repaired.
After getting them to finally issue a case number, I decided to turn the Xbox on again and see what happened. Wouldn't you know, it ran fine for 5 days before crapping out again. So, with that I used the emailed mailing slip and got it sent on its way.
Since I'd discovered that the machine could go days without freezing again, I decided to ring back customer support and update the case file because I didn't want the engineers to return it to me because they'd run it for a day and it hadn't crashed. Well, OMG, apparently updating a case file is, like, totally freaking OUT THERE as the whole notion completely confused the person I called...
( 3 minutes or so into the converation )
Them: "So you want to cancel your service order?"
Me: "No. I just want to update the case file. I want to give more information about what's happening with my box."
Them: " You want to know what's happening with your box?? Our records show we haven't received it yet."
Me: "No. I want to add more information to what is wrong with my box."
This went on. Of course, it's nothing compared to the fact that when they mailed my Xbox back they completely failed to furnish me with a tracking number, and I had to go up the chain to a manager who admitted they didn't know why there wasn't a number. He also promised to look into the employee who on a previous call had given me a completely fictional tracking number when I inquired about the missing number. Perhaps I scared her.
In conclusion: Good luck.
That may be my longest post on B.org ever.