If you try and save a project using: save as > copy media with project > create trimmed copies of source media — Vegas gives an undetermined error everytime. I have narrowed this down to a cineform codec issue with Vegas 9. It works fine in Vegas 8. As soon as I remove all of my Cineform files in Vegas 9 it works again.

Sony has acknowledged the problem in a recent support ticket : "I spoke with development on this issue. It appears to be a known issue and they are working on a fix for it."