You need to update your meta tags. You're still running the default comment from out of the box. "This is a computer discussion forum powered by vbulletin" "For more information go to(and the link to VB
If you add something like:
computer hardware, computer security, computer networking, website hosting,
And so forth. The search bots will be attracted to and able to better sort your forum out.
And look out for the spammers. They seem attracted to new VB4 installs.