Showcase Strategy Query won't start, Excel locks up

Office 2003, Showcase 4.5. I am unable to view or refresh Showcase Queries
from a spreadsheet. This file used to work, we pushed out some O/S and
Office patches and now it won't work on those patched machines. However, it
will work on unpatched machines, and even when we apply the patches to those
pcs, the file still works??? Has anyone had any similar problems with an
add-in program like this? Any comments or suggestions are appreciated.
Thanks.