I think there is a bug in the log-in function because I have to do it twice everytime. The first time nothing happends, I'm still not loged-in an have to repeat the process a second time, then it works =)

That happens to me as well... I thought it was because I was hitting 'return' instead of clicking the 'login' button. Hmm... I don't know enough about technology to look into this.

Try going to http://worldcubeassociation.org/forum/ first instead of http://www.worldcubeassociation.org/forum/ The forum software is configed to not use the www part, so the first cookie gets set for with-www, redirects you to non-www, where you have no cookie, so you login again.