Ian,
I replied directly to you. But for anyone that finds this the solution is generally to reset your password from the auto generated one that we send during the registration process. You shouldn't NEED to do this but sometimes when you copy/past the generated password windows will grab some extra spacing around the password.
You can reset your SGP password here:
http://mainsequencesoftware.com/Account/ForgotPassword
Thanks,
Jared