nods

I'm going to try to load them on another computer and see if the files at least still work.

When I backed up my folder, I backed up the entire content folder including the Data files, so that the geometries would remain intact. 

I don;t know what's causing the problem exactly, so I don't know what's missing... And the bug report people aren't replying to me (again - which is why I submitted through the site last time and not a bug report - already checked my spam filters).  I don't know if it would be a problem that the drive letter changed and then was changed again? That's the only  thing I can see different from the original startup files from last time.

Smaller files work too, so I'm wondering if my 4 gigs of RAM STILL isn't enough...