Holy cow.  I did just click Microsoft Discussion and not Sony Discussion right? 

Where'd all these Sony fans come from?  O.o

*slowly backs out of this thread...*

I took my copy of GTA IV back after it gave me a disk-read error twice. I had the receipt and they gave me a new copy. I love GTA IV so much I'll just keep it if my other copy is on the fritz.

The only other game that happened to me was Mass Effect. I just flipped that damaged copy on eBay.

It could be the 360 and when I make my move and get set up, I'll buy a newer 360 anyhow and just keep this one in my living room.

 I lost Assassins Creed that way. I always wondered, why the hell didn't MS design the console with one those things you can snap the disc into? Something that stabilize the disc so that a little bump wouldn't cause the spinning disc to go out of control.

Scratches on Xbox 360 discs have nothing to do with the disc tray and everything to do with the fact that some basic micro rubber pad protections around the lens are just missing, probably to cut costs : it was very well documented by dutch consumers watchdog programm Kassa : http://youtube.com/watch?v=rlQYkaXv8RU

Damn this is the worst thing to happen than having a RRoD. Glad this never happened to me.

wow i feel bad for 360 owners rro & scarching disk microsoft isnt cut out too make hardware.......

That really sucks that it scratched up your disc.

As for the other people who moved their system while the disc was spinning that is definitely a no-no with the 360. This problem was talked about long long ago (http://www.llamma.com/xbox360/news/Xbox-360-Game-Disc-Scratched.htm ) That is from 2005.
That's why MS started putting those stickers on the dvd drive tray that say something along the lines of "Remove the disc from the dvd tray before moving the system". (note: I'm just translating the Japanese from my sticker as I don't have a sticker in English)

excuse me but how the hell a system can scratch your disks?I heard this ebfore but I thought it was a joke.

Edit:never mind I jsut watched the youtube videos...This system is seriously in need of a redesign if they haven't fixed it yet

People please ensure the 360 is horizontal when playing games, to minimise the risk of game disks scratching.
When the 360 is up vertically and playing game disks, the risk of disk scratching are increased significantly.

What? So Microsoft fans can swarm the Sony forum, but when the reverse happens it's shocking?

I suppose that speaks volumes...