WinAVI DVD Copy not working

I have only one drive (CD+/-RW), so I first copied the main movie to the DVD_Video folder on the hard drive. When I tried to write it to a blank DVD-R using WinAVI DVD Copy, it stopped responding and showed no progress. Other computers with DVD-ROM can not read the DVD-R. So far I have ruined two DVD-Rs. Anyone know what's going on? Thanks!