Is there ANY way that I can change my m4v itunes files to an unprotected file that I will be able to burn to a dvd?? I feel like I've looked everywhere. I even bought tunebite which isn't compatible with windows vista, which I didn't know until after I spent $34 on it. All I want to do is burn these stupid videos I bought. If I would have known that you couldn't burn them to a freakin dvd I would have never bought them, I'm at my wits end!! Please please please can someone help me... and if you say anything about tunebite I'm going to be really angry!!

Don't know if you still have this problem, but I had similar issues when I switched from Win XP to Win Vista. And I'm going to tell you smth about Tunebite, so don't go angry :)
On XP Tunebite worked perfectly, but on Vista it was completely blind on the video aspect.
After a few emails back and forth with the support team, I found that if I disabled the hardware acceleration on my video card, I could convert w/o problems. You could try this, maybe it helps

I am using an Intel on-board graphic card.