You're missing the vb3-settings file, it seems. Although the latest file I attached has the modification steps, you'll need to check rsuplido's first post in this thread for the missing stuff (don't forget to grab postfeed.php too).
Let me know how it goes - I'm still running this on vB3.5.4 and WP 2.0.2, and it would be a nice surprise to see if it's forward-compatible