Bob,

There is no misconception on my part. I own a Title Company as well as a CPA Firm and my clients are predominantly foreign nationals who deal with real property here in Florida.

The withholding "source" is the Buyer (Transferee), who reports the withholding on Form 8288 which is the Buyer(Tranfereee)'s Tax return, which attaches Forms 8288-A's for the Seller(s). (Analogous to W-3 being remitted by an employer with W-2's being issued to employees). 

This is straightforward a programming issue that needs to be resolved (similar to the 1042-S Submissions that are possible with ATX but not Proseries).