DVD's won't play on my iMac

Ok.

I have an iMac. I also run Windows 7 on the machine using BootCamp. Anyway. I was watching Family Guy before and paused the episode to go and do something else, when I returned to watch it, DVD Player could not play it, then I noticed it wasnt showing up on the desktop either. On my Windows portion, it was showing up, however not playing on the Window's side either. I haven't restarted my computer as I running a packground program that is working away. I've read that others have had this problem, but no one seems to have had BootCamp, so I thought i would ask here.

Cheers,

Matt