I'm not sure what causing the problem but I have two systems with Nero 8. I don't have a problem generating Nero Digital files on either system but when I use show Time to play the videos on one system the mp4's will either play choppy or not at all. On the other system though they play just fine.
I'm sure it's some sort of a conflict in the codec or something like it. but I don't know where to look or how to correct the problem. I've tried reinstalling Nero but it didn't help. I would just like to know what could possible be interfering with Show time to keep it from playing the video properly?