I had a problem after registering, where I was automatically logged in to the main screen OK, but when trying to access the forums was prompted for password again, which consistently failed.
A mail to the administrator produced no reply.....

I have since discovered the problem by registering as a different user.
It seems due to the fact that my original password had a "/" in it - this was somehow screwing up the system (sad because I like cryptic passwords).
Registering again with a more conventional alpha-numeric password cured the problem.