I used an mpeg file that I had captured from my sony video camcorder. Below is the info that shows under the file when loaded in Vegas.
720x480x32 23.976 fps
field order= audio 44,000hz, stereo MPEG layer 2
The only thing I did to this file was cut a few seconds off the end and adjusted the audio volume. After rendering at the same setting as the original, per help file notes, the files ends up being 858mb. I've tried different settings and everything ends up around this size or if I do as avi it ends up being 14gigs. Any ideas would be greatly appreciated.