This is very strange that no address of IRS on the cover page. Asking Bank name, account number and copy of passport. Does IRS ask these? I don't think so.
The fax letter looks like fraud because it has no address, use different fonts, and mentions (1) No date ("MAY 2009"), (2)"return within 1 (one) week from the receipt", (3) "USA Citizen", (4) "helping us protect your exempt status", and (5) "have all account holders , sign and date the form" etc.
W-8BEN Substitute Form is really suspicious for asking "Mother's Maiden Name, Spouse's Name & DOB, and Bank Name & Account#, and Passport." The question asking for SS# puts "Cedular de Identidad no" (is this Sapanish?)