apparently the Blackboard system is not just a Scotland or UK thing as I have to use it as well at my uni...
I've had many problems with it as well though, mostly with the courses and exams I was participating in, but sometimes with logging in as well. So far my uni always could help me out with providing me a new password... Maybe you could try contacting someone from your uni, who deals with the whole Blackboard system. There should be at least one person to contact with any problems!
I never really trust Blackboard anymore. Whenever I have to sign up for exams, I always do it manually... it happened to me before that I couldn't participate, because Blackboard messed up

.
Good luck anyway!