You only have a few more days to get your discs replace for free so you need to mail them immediately.
http://www.xbox.com/en-US/support/sy...nt-program.htm
Also I got mine back today and they seem to be sending out 1 month of free XBox Live Gold extensions with the returned discs, so even if your disc is playable it might be worth it for that free extra month of live for the price of 41 cents.

Yeah, I've been draggin' my ass on this since I finished the game and it plays fine.

I haven't opened my Halo3 limited set yet, what's all this then?

#3 on google
http://technologyexpert.blogspot.com...imited-ed.html

My game stopped working just last night. I am screwed for the free replacement? Any other options for getting my disc replaced?

I think you can still get a replacement disc now, but it will cost you $10 now.

I went ahead and sent in my disc. Worst case they just send it back. It should be post marked today.