Thanks for all the input.  One funny thing about this save error - it does not occur when I save with the render setting at "fast preview" with the default render (no antialiasing).  It appears to happen when the render setting is at normal with antialiasing and only happens after the render's been running a while if I try to save incrementally.  If I start the render and pause the render and save, it saves fine. Let it run a while, pause, save, then the error occurs.

I have since reduced the file size to some 160megs and still get the crash on the Dell Optiplex with 2.5 gigs of RAM but did not on a Latitude Laptop loaned from work that has a mere 1 gig of RAM.  Strange, huh?

It seems that I can work on this file fine on the Optiplex, adding lights or other polygon groups, I just can't do a quality render on it with this particular file.  Admittedly, one texture has a 50meg photo which may the cause of all this, but I've been working on this file for at least a month now with the high meg photo texure, but only yesterday had the first save crash.

Oh well, live and learn, right?  At any rate, thanks for the suggestions!!