XVID to DVD transcode using Nero Vision slightly choppy?

I have two 350mb Lost epis that I am trying to burn to dvd...when using Nero Vision 5 though I am first having it place the dvd files on the hard drive...the transcoded episodes are ever so slightly more choppy than the original xvid files...they are not choppy like stuttering...instead it's more like comparing a video game that runs at 40fps vs. 30fps...on Vision I set all options to "automatic" (quality is "fit to disc", etc) except for encoding is 2-pass VBR...is it normal for this slight degradation in fluidness to occur with what I am trying to do? Any recommendations for another program to try?

And it's not the burn or quality of dvd since I am seeing this when playing from the hard drive...and when using "fit to disc" the VideoTS folder ends up being 4.3GB...

 

How many FPS were the AVIs and what are your final DVD's FPS.