Hey DrPepperfan, I actually work with Microsoft Xbox Tech Support. The answer you were given is true, however not the full story.
Can I ask, did you play your games while it was Vertical or laying on its side?
The 'perfect circle' scratch on any game disc is due to one reason, and one reason only: movement of a powered on console. Unfortunately this is bad for gamers that like Guitar Hero and jam out while playing. If the console is in tower position than you're likely going to wobbling it, and in some cases it will fall over.
Now the issue here is that the 360's inner disc laser tray has to readjust when it is moved, and that movement... well something is going to get scratched, and unfortunately it's the disc, and in perfect form.
Don't think that I am harking on you here, just looking for info man.

Btw, you did get those games replaced right? Microsoft has it's own Disc Replacement plan, for it's games... while nearly all other game manufactures have their's as well.
Edit: On second thought, I think I talked to the original poster today, of that first post on here lol. If you post here, holler.
Later.
This post has been edited by Lone Wolf: Aug 31 2007, 04:32 AM