I can only speak for myself but as a Moderator (not in the VB.Net forum), I am already spending a lot of time (several hours a day) reading every single unread starter post in the forums I moderate. So when I reply in a thread, the likelihood that I re-visit that thread is very low unless it is particularly interesting for me (in which case I will set Alert Me).
In other words conversations with me in threads I am not particularly interested in will not happen because I won't see the replies.
The assumption is that other people (who do not read every thread but just the ones where they find the title interesting) will come in and respond to any follow-up in it.
You should not post new threads though for the same question or follow-ups to the same question. As David wrote, if there is a (completely) new question, then start a new thread.
WSS FAQ sites:
http://wssv2faq.mindsharp.com and
http://wssv3faq.mindsharp.com Total list of WSS 3.0 / MOSS 2007 Books (including foreign language)
http://wssv3faq.mindsharp.com/Lists/v3%20WSS%20FAQ/V%20Books.aspx