When you register for the forum, please make sure that you add http://www.nyctransitforums.com to the list of allowed senders in your anti-spam program. We send out a confirmation e-mail with the registration, and if your spam program eats it, you won't be able post.
It's a totally automated system, so if you send out those "Hi, I'm protecting myself from spam, please confirm" or "How many puppies are in this photo?" type letters, you will not get a reply, and you won't get your confirmation letter either.
So please be sure and take whatever steps your anti-spam program requries to make sure the confirmation letter gets through so that you can complete your registration and be able to post.
As always, if you have problems registering, use the "contact us" form and we'll work with you to get the issue resolved.