I used 2 out of 3 vouchers for the CSWP exam, passed segment 2, failed segment 1. When I tried to retake segment 1 (a few months later) it says my voucher is invalid?!? They expire in June, so that's not the problem. All of the codes I got messaged to me are labelled as "invalid". What is the reason for this? It clearly stated I can retake failed segments, but when I entered TesterPRO neither the examps or the vouchers were there.