Macroblocks seen in final MPEG2

[cmoorbutz]

I captured some old 8mm video via my camera. Uploaded via firewire, did some color correction etc. to the footage. Rendered the video in Sony Vegas to an MPEG 2 DVD architect stream for use in DVD Architect. When I view the MPEG file with windows media player is looks good. When I bring the MPEG file into Architect and view the same file I see lots of macroblocks in parts of my footage where the 8mm film had alot of motion. Obviously when I author the disc I get the same macroblocks. What I have figured out is that this is happening in Vegas during rendering. I brought the AVI file straight into Architect, let the conversion happen there and it worked like a charm. The problem is I need to edit out some parts of the original AVI which is my need to render to the mpeg2 from Vegas. I then tried editing, saving the file from Vegas as an AVI and then bringing that into Architect. Again the same macroblocks show up.

Can someone explain to me what is happening with this. I've done thousands of feet of 8mm film before and this happended to me one other time. I just can't remember how I fixed the situation. I'm frustrated because I want to finish this project but I refuse to let it go like this. Any recommendations or settings I could use to eliminate the macroblocks in rendering with Vegas. I've even tried a CBR but that didn't work either. Any suggestions I would greatly appreciate.

[lordsmurf]

Use more bitrate. What resolution are you at? What current bitrate?

[cmoorbutz]

Resolution is 720 x 480 and rendering at a single pass VBR average 6000, max 8000.