Handbrake Help

I'm trying to rip my home DVD library to my Macbook Pro using 10.8 OS. I've downloaded Handbrake which exports a .m4v file that won't play with any apps on the computer (VLC, QTime, Miro). I've tried manually changing the filename to .mp4 to no avail. The error I get is the file format is not recognized. Is there something I can change within the Handbrake settings or anything else I'm doing wrong. Any help you guys can offer is greatly appreciated.