I created a video which has a montage section with JPGs. Vegas seems to have problems rending the JPGs if they are large. I have been re-sizing each of the photos to a lesser resolution which seems to be a band-aid fix.
When I watch the preview of the project, you can see the fame count increment but when it gets to the JPGs that crash it adds a "...." to the frame count. It crashes at the same jpg/locations every time.