First some background:
I used a "camera-tracking" program to match the camera movements of a video clip and imported that into a 3D program which I used to create some 3D objects to overlay on the video. The purpose is to try to make it appear that the 3D objects are in the video.

Here's my problem:

- If I overlay the CG clip over the Video clip in Vegas Video 4, it is synchronized OKAY only for the first bit and then it starts getting out of sync--the motion of the CG object is not matching the camera motion in the video clip. It's as if there's a slight timing offset on the 2 clips.

- If I use a very basic editor to overlay the CG clip on the Video clip, it is synchronized perfectly.

I've double-checked and the frame rate and aspect ratio are identical on the 2 clips.

Is there some sort of timing or timeline setting in Vegas that I'm missing? I tried messing with the timecode settings to no avail (though I'm not very experienced with those settings).

I can get around this by using the more basic editor, but it would be much easier for my workflow to do this in Vegas.

Any suggestions would be greatly appreciated.

Thanks.