I came across that document as well and started to question the audience SmartAdvisor was intended for as well. I have see the invalid UserID error a few times, but have been lucky enough for it to get past that a few times by just re-entering my credentials. Unfortunately my Transactions fail with the "Complete with Errors - KTN Pending" message. I tried to open a support case with Cisco through TAC since I could not find another way to open a case. They have now directed me to the "Get Partner Support" page found here
http://www.cisco.com/web/partners/support/index.html
So I think this re-enforces the fact that we as Cisco end-users really are not the intended audience.