Yes, absolutely, hmmm, I am stymied now! Only other thing I can think of is - is it possible for you to save to CD? If that is possible you could then do further checks on your software's installation.
Ah! Sometimes I wonder about myelf. I gave all the critical info except the thing that seems to have mattered. I'm not using Photoshop. I'm using Picture Publisher (10). Evidently it doesn't like saving large files in .psd--although I've never had this problem with it before, but then again, I've never tried saving a 66MB file in .psd with it, before.
Curiously it has only ever given me problems with this one file--which. by the way and again, it saved ok on my backup disk--but for some weird reason kept telling me my principle data disk was full.
Anyway, I took the hint, Diemmess, and opened it with Elements (I have that, just in case) then saved it--no problem. Will do that if the problem ever reappears.
(Why, some of you may ask, do I not use Elements all the time? Sorry to all you Adobe fans, but, even as old as it is, I'm a long-time fan of Picture Publisher. Tried Adobe--and tried it, and tried it--and hated it!)