OK, let's think about this. If it were storing the info elsewhere, it would
be intact, unaffected by your renaming and unzipping, right? And since you
unzipped an exact replica of the solution as VS had last seen it to a folder
with the same name, nothing could have changed that might have pointed to
that information, right? I'm stumped.

FWIW I tried zipping, deleting, and unzipping the folder, and all files
opened up as before. Then to exactly replicate your case, I renamed the
folder and unzipped again, creating the original folder. Same outcome. Mine
is a web project.

Third experiment: Open the solution Foo and open several files. Close VS,
and copy Foo.suo off to the side. Open VS and close all files, then close
VS. Replace Foo.suo with saved copy. Open VS, and all files open as before.
Conclusion: This info is in the .suo file. If you look up the file "type"
you get VS Solution User Options (suo). It's a "hidden" file. Are you sure
you are preserving it?

I knew I'd read something that explained the roles of the various files.
Here's one (watch out for wrap)...
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dv_vstechart/ht
ml/vetchwebprojectssourcecontrolintegrationinvisualstudionet.asp

Jim,

Thanks for the info. Unfortunately, my version of PKZipC, even though
I am using the -attributes=all option on the command line, does not
include the .suo file.
(I'm doing the zip from a script). If I do the zip from PKZipW, the
.suo file is included.