Yes you posts are visible!
to the HUBB. You need 5 posts in order to send private messages.
Why not just ask/reply to post in this public forum? PMs are for stuff that is private. When somebody sends me a PM asking for information that they could just as easily ask for on this public forum (or search for: using the search function at the top of every page), I suggest they ask publicly. There I can choose to reply if I wish, rather than being "obliged to" because somebody contacts me privately. And you're more likely to get a good answer, because I won't necessarily know the answer.
I've taken the opportunity to delete some of your posts where you're just testing the software and aren't asking/replying to specific travel/vehicle specific questions. It will help others to find what they're looking for.
Here are the answers to some frequently asked questions:
http://www.horizonsunlimited.com/hubb/faq.php
It also helps if the subject line of a post makes it clear what the the thread is about.
If you click on your own name in a post, there's the option to see other posts you've made. You can see if anyone has replied, in the case of your question about the Mongolian festival, nobody has:
http://www.horizonsunlimited.com/hub...le-leave-75910
The Northern Asia section is better for Mongolia questions, rather than "Travellers seeking Travellers"