I've already gotten rid of the Vector package of tovid, and installed the newer one (tovid svn-r3493) from subversion. So, I can't give the exact error it kept giving me. However, whether I ran the gui or ran it from command line, it gave the same error. The error came about when it was trying to encode the video, claiming that the there was some sort of mismatch and the video could not be encoded. I did successfully encode the same video with the newer tovid, however. When I checked the Google Tovid Group, there were some posts on this subject, stating that due to ffmpeg's perpetual evolution, that many encoding issues could be solved via installing latest tovid from subversion.