I recently began having trouble with Nero creating stuttering "coasters" when I convert YouTube video clips to DVD. The stuttering problem was present in both versions 6 and 7 - I didn't try 8. I contacted Nero and asked for assistance but they didn't seem able to help.
I eventually narrowed the problem down to Nero's annoying habit of recoding everything. My data files were playable in every other player except Nero Showtime. I needed to save in a better format.
Yesterday I discovered Internet Video Converter (Standard) a free video file converter which handles a lot of different formats. Unlike a lot of conversion applications, this one was very straightforward (literally 3 button pushes) and I was able to convert to DVD. Better than that, it even supports encoding to PAL DVD - used in Australia and the UK.
Nero still wanted to re-encode the video files but at least they came out on my TV without a stutter.