Rolling a new release.
Fixed the issue with configuration; seems vbulletin did some under the hood changes at some point which broke it, now confirmed to work on vbulletin 4.1.1
I've also added the avatar of the top poster to the top of the widget and the top posters name is displayed in a larger bold font, centred in the middle of the widget.
I had planned to add some more features, however it took me forever to track down the configuration bug