Mine wont play at all

Same here. Amirm has said there is a fix coming, when? i don't know.

Invalid disc.

already being reported an discussed here

http://www.avsforum.com/avs-vb/showthread.php?t=826140&highlight=relentless

Yeah, there seems to be a problem with compatability issues. I just got the disk last night from Warner's little coupon code sale a few weeks ago. It was the only disk that didn't work in my 360 add-on. I think I'll just hold on to it until those patches come out. If that doesn't fix it, I'll have to return it to best buy or some other store around here.

Boil it then try it