Vegas 6.0d, using external preview via firewire. I have some clips that were loaded directly from a camera into Vegas using Vegas capture. I can put these on the timeline, play them, and the clips show in both the Vegas preview window and my external video (via firewire).

I also have some clips that were loaded onto a Mac with FCP, and then portions of them were rendered out as .avi and copied to my computer. I can click on these clips in the Vegas explorer, and they auto-preview fine. I can put them in the timeline, and they will playback in the Vegas preview window fine. But they will NOT preview on the external firewire video display. When it comes to those clips, the external screen goes black. The Vegas Preview window still shows "Preview on External Monitor".

The media properties look identical for these clips as the ones captured directly on my system: 720x480x24, 29.970 fps interlaced, DV.

If I add an FX to the clip, say, Black Restore, then the clip will preview on the external video (and the Vegas Preview window says "Frame Recompressed".

If I re-render the clip out as AVI, then bring that into the timeline, it works fine in the external preview.

Does anyone know if FCP generates some sort of non-standard header for an AVI file that would cause such a problem?