Have a template to process the saving of a document back to the file system
of another application (i.e. a special save button that saves the file on an
IIS server using webdav).

The problem I am having is that the template (also on the same IIS server)
does not appear to allow multiple users to have a document open (using the
template from the IIS server) at the same time (with Word 2000 on the client
PC).

Does not appear to be a problem when Word 2002 is on the client PC.

The user sees an error message saying that the template is locked by another
user and it (the template) can only be opened read only - which would not
allow the macro to be executed.