Jon is, unsuprisingly enough having had a look through these forums,
on the ball.  Unless the rapid firing is caused by the uncompleted
event handler (some sort of timer going on, which will build into a
crescendo if you stack multiple jobs causing eChina Syndrome) all you
really need to do is queue up the work jobs and handle them sensibly
and timelily... umm... in good time.

Try looking at the MS CCR (http://msdn2.microsoft.com/en-gb/robotics/
default.aspx) if you want a fancy pants solution to this problem.
Threads made easy (for a given subset of thread tasks, massive joins
not included, please read the small print).  Don't be put off by the
fact that it says 'Robotics' all over it - that's just the weird
implementation MS have chosen for this awsome extension.