Handbrake says encode finished but there's no file?

I've been using Handbrake for a little while, copied a DVD just yesterday, but I tried to copy another last night and it didn't work. I pressed start and after a second or two of "scanning queue" and "muxing", the "encode finished" box popped up, but nothing was actually accomplished. I downloaded both VLC and Handbrake again and deleted the old ones, but the same thing happened. I tried again this morning using Mactheripper to rip and then Handbrake to compress - but same thing again. Does anyone know what's going on and how I can fix it?