I was getting rather tired of waiting for NVE3 to encode avi, mpg and wmv files before burning them to a dvd. I finally found the solution. I decided to try the WinAVI converter and it drastically reduces the encoding time, especially on the wmv files. And the picture quality is slightly better too.
All you do is pre convert the avi, mpg or wmv file using WinAVI, then add the vob files to NVE3 and burn. You'll save about 50-70% on time!