jQuery v1.3b1 bug? in animate callback

jQuery v1.3b1 bug? in animate callback


I boiled it down as much as I could. Test case is here:
http://newlevant.com/marion/jqueryplugins/concentrationBug/
Calling animate like so:
animate({opacity: 1.0}, flip.time, function () { ... });
And if flip.time is 0, subsequent calls don't wait for the animation
to finish before calling the animate callback.
Have not submitted a bug report (new to the whole system), but will if
you think I should.
(jQuery is fabulous by the way. Plugin where I found this bug is here:
http://newlevant.com/marion/jqueryplugins/concentration/ )
Marion