[Google-Desktop] Indexing Multiple Outlook PST files

I may have solved a small mystery that may be troubling others.

Because of size limitations, I've been forced to create multiple
archive files, one per year going back to 2002. GDS has not been very
successful at indexing them within the Outlook plug-in search function
(they often appear in the results queue but cannot be opened).

I think GDS is only capable of indexing a single PST file within each
folder. I have created a separate folder for each archive file, and
they now seem to be getting indexed successfully.