Call Xerox, get 2nd level support and provide them a wireshark trace of the attempted scan then.
There are at this point no issues with scanning using SMB, FTP or SMTP with any known service on the Connectkey family of printers running any recent firmware (They all start with 073)
SMB port 139 for Vista or older. 445 for Win 7 and newer.
Username exactly as listed in the folder props as seen above.
Folder not located within the a Users Profile (C:\Users on any current Windows box.)
Time and date on the printer within 3 minutes of PC time if HTTPs is enabled on the printer.