This is from the rules:
Please note that IT CAN TAKE UP TO AN HOUR for the forum software to update your account when reaching Full Member status. This means that you may have to wait a short time after reaching 5 posts, before it becomes possible to post in other forums, use Private Messages or have a Signature.
0 to 5 posts:
New Member.
Cannot post live links. (In order to post a link, just put spaces in it like this: www. example .com)
Cannot use Private Messaging (PMs).
Cannot have a signature.
Cannot post images (photos) if linked to on another site.
After 5 posts:
Full member.
Members can post in all open forums, use Private Messaging, and can have a signature.
Note that some forums are private: access is for special membership categories.
Perhaps it will just take some time to register with the system.