I'm using Vegas 6 for compositing several still images into one image for export. I have 2 tracks of images created in Corel Draw, 1 Vegas text track, and 3 tracks of Vegas-generated noise media (great stuff, by the way!).

Initially I set my project properties to Progressive/Square pixels. When I set the preview window at Best Auto, I can see all my tracks correctly. When I change it to Best Full, 2 of the noise tracks are not visible. Changing to Best Full/.9091, all tracks are visible.

This isn't the usual question about why images look squashed at the wrong aspect ratio. This is an abstract composite so the exact aspect ratio isn't crucial. I'm just curious as to what switching between Best Auto and Full is doing to 2 of the noise tracks. I tried checking/unchecking "maintain aspect ratio" on the 2 disappearing noise tracks and it didn't make any difference.

The noise tracks are some clouds (always visible), a starfield and lighting (these last 2 are doing the disappearing thing.)

Thanks for any enlightenment.