I just started playing this 2 weeks ago and tonight as I completed a mission it plays a cut scene and won't advance any further.

The scene stops and I hear the disc slow down or stop. It then goes back to the Dashboard. Looking at the disc I can see some tiny marks such as grooves on a record. I'm careful about handling my games and I'm sure I didn't touch the data side of the disc.

I was able to play online afterwards. It's just my last saved checkpoint is now stuck.

So now what?

Alright. I got it to play through. I just wiped over the marks with a tissue.

Usually I don't like doing that for fear of making it worse but I guess it worked this time.

Glad we could help.

My work here is done.

Glad you got it fixed, now put down the keyboard and mouse, stop playing single player and get in some ranked matches on live. This game is a blast online, especially war. The new map is really good for war too. I am almost to my 2000 Kills achievement and very much looking forward to my next 2000+.

Wow, I've been meaning to jump online....I actually completed single player last night (I usually like to go through the single player first)

I did the same thing, beat single player now doing multi as well as going back through on Veteran. I know it's buggy and is different but this game is great. I prefer COD2 single player but COD3 multi is way better. The new map is pretty great too, get 12 players on War and it's great.