OK, now that Leigh nailed the issue, I will report it.

There was a non-blank entry in the Edit Defaults "Save directory" field. GridView 9.0B was ignoring this entry when using the /xdw runtime parameter, and was "incorrectly" sending the Excel file it created to the XDViews folder under the data directory.

Once 9.0C was installed, GridView started sending the Excel file "properly" to the path in the Save Directory field. This fix caused my client's problem.

We resolved the problem by blanking out the entry.

Steve