I have downloaded and installed DS-PCB V8.1 but when I try to run it I get an error message "failed to authenticate" but I have no idea why. I have had to roll back to V8.0 which put me out of step with the rest of my team, most of whom have upgraded. I have tried resetting my password which worked for one of my colleagues but it makes no difference for me. I'm running Win 7 Pro.