You must activate your registration (you should receive a mail), only after that you can post.
There are a few possibilities:
a) You have some half-intelligent spam protection which decided that mail from this forum is spam: check your "spam"/"bulk mail" folder. Hopefully you do not have automatic deleting of spam...
b) You entered a wrong mail address when registering so the board mail never comes.
c) There are occasionally some people who say they did not receive the confirmation mail. I think that the reason is probably not on this board (since most of people do not have these problems), but there can be some problem with board (although I do not believe it).
In any case: if you are unable to register properly, it is worth trying to use another mail address (I mean an address by a different provider - there are many possibilities on Internet where you can get a free e-mail). And as I said before: remember that some stupid spam protection program can decide that the board mail is spam (so deactivate spam protection or check arrived spams manually).
Mirek