Sylv33 wrote: loops through all rows in a table The engine should do that; you shouldn't.

Thanks to the both of you for the explanation! I ending up changing all the relevant code to use isnan(f) instead of direct comparisons and everything works fine now but I was still wondering why a direct comparison with a NaN always returned 0 on my compiler. Now I understand! :-D

What you are looking for is an MSDI model instead of an MDI. http://www.mimec.org/articles/mfc/msdi[^] HTH SM

Sylv33 wrote: Has anyone else had this problem?? Sorry, no. I've got a solution that has 8 projects in it and the "build only what changed" works fine. If anything, it occasionally misses a dependency and doesn't rebuild enough. Before you ask it to build, go through Explorer and look at your date/time stamps on your .obj files and check what they show copmpared to the date/time on the source files. Maybe something else is messing up your file dates. Judy