Robin Hoods Playground

I updated a benq to 1.61 and new ixdef file. I tried to play MW2 but I'm getting an error "cannot read media" or something along those lines. THe other games seem to play fine. THIs is the only wave 4 game I have.
ANy ideas of what could be wrong?
thanx

if you have other backup games that play
then it has to be something with this burn
i would reburn the iso
burn slow 2.4x
if you can check your backup in a different console