Actually, since your login forum account is the same as your in game account, changing your forum password changes the in game login, so you don't have to create a new account. I know because I recently had to reset my password, and I keep forgetting that I changed it, so I always get it wrong the first time. Once I type the new one, I can get in. 
When I first tried to join, I remember having this problem. I ended up reinstalling the game first, and then creating a new account, but since I tried both of those at once I'm not sure which one fixed the problem. They should try to reinstall the game first, and if that doesn't work, they need to create a new account.
I tried to uninstall the game and install it again, but it didn't work, so I tried the torrent which did't work either... and I created new accounts to, I have like 3 now... :/
