Newbie here first render was .avc good video no sound second Render was mt2s I think video and sound but the video from a b camera speeds up for a second and then slows down. It does this ever once in a while during playback. By doing this the sound is out of sync. Any suggestions I'm lost.

Forgot to mention I'm trying to render for bluray

Render twice. First for video AVC. Second is AC3 for audio. Make sure to use the right AVC template. Vegas 12 is PRO not Studio.
Also NAME the 2 files the same so when you bring the file(s) into DVDA (If that's what you're using to author and burn they'll come in together so name as ((example-myvideo.AVC and myvideo.AC3)))

I shot the video with Sony ea50 and a Sony HDR-220 both in 1080. I also rendered the video the first time using Bluray 1920x1080 60i 16mbps Video Stream under Sony AVC/MVC. I had read somewhere about doing the audio separate but could not find it again. Thanks for all your help.