Since you are using Nero Vision Express, I take it you are converting a video to dvd format, then burning?
If you have the complete Video_TS folder, ready to burn, you might consider using ImgBurn. It is a free burning program, excellent for burning video or anything else for that matter. Beef gave you both the link to the program and a step by step tutorial on how to do it.
If you want to do this with NeroVision Express, it would help us if you could post the log of your failed burn.