I've also noticed such behavior of Google Toolbar in Firefox. So now if I want to disable it - I simply disable whole Google Toolbar Add-on and restart Firefox :)

I removed the PR Rank tool in April of 2008, and removed the toolbar altogether about six months ago. I know it seems like web publisher malpractice, but I have been so much more effective since I decided I didn't want Google knowing what I was up to, but more importantly I can ignore that little green bar and concentrate on creating great content. Sure, I still pay attention to the SERPs, but that is where the bread really gets buttered!

Jeez, dude, dragging an ancient (silly) contest into the comments here is really weak on so many levels. And let's emphasisize "ancient" to keep us away from "pointless."
Good luck in knocking out Leger.
And that system you are using (stumperjack, stupidpawns, or whatever they call it)is a circle-jerk - FYI.

.. not just the Chinese then :)

My question is - WHY did you install it in the first place? :}