Faster sound and picture after using nero 5.08 to burn VCD½

[Foppas1]

I start with encoding the movie (avi format) in tmpgenc and when that is done it play the file on my computer and everything is fine, the sound and picture is perfect. After burning the VCD with Nero 5.0.8 or something and playing the file on my NAD- T531 standalone dvd the picture and sound is faster than it was on the computer. I burned the movie in 12x on a plextor cd-writer with vivastar cd-r disc's wich support 12x.
Please tell me what to do?

[Foppas1]

Nero does'nt work with avi files , only dvd or other mpg formats.
Do you know how to determine if a file is vcd/svcd or dvd , the fileending is mpg on both?