I too have had this problem multiple times over the past three years. Upon verifying the transaction, a CONFIRMATION page stating that a successfully submitted transaction took place and displaying the transaction number (in bold) and a button reading, "Print Transaction". Clicking the "Print Transaction" button results in the display of a page asking for a password. I've encountered this exact problem at least twice on Macs and once was on a PC. This particular instance occurred in July, 2013. It took 8 calls and over 45 minutes to reach someone at the FRB using the number displayed on their website, 617-660-4782. All this while sitting at the computer in the Seller's living room. After being repeatedly connected to voicemail, I lucked out and a representative of the FRB answered the phone. He reported to me that the issue that we were having, described above, are a known and indicated that he was unaware of any plans to rectify it. I was also told that if I want a paper copy mailed to me, that I would need to email the following information along with a written request to the FRB:
Name
DOB
LTC#
Driver's LIC. #
Transaction#
Serial#
This seems like an awful lot of information to be transmitting in an unsecured email. I will say that the representative that I spoke with was courteous and helpful. He even provided me with his direct email address to send the request to.