Toad hangs, crashes or displays error "Timeout expired" when adding a cross query to the Export Wizard (4308060)

A cross query (xquery) between Oracle and Sharepoint executes OK in the Editor. The query itself can take up to 20 mins to run, but does return expected results. After adding this query to an Export Wizard (in Automation) and clicking 'Next' , Toad will hang and eventually crashes. On occasion, Toad will produce the following timeout error rather than hang:

"Schema read error:
Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding"