UI 1.9 Spinner - No change event in IE if only spin once

See http://jsfiddle.net/XseWc/4/. Reproduced with jQuery 1.6.4, 1.7.1, and 1.7.2 in jsfiddle.

In IE (IE6 - 9, not tested in IE10) if you hit the spin image once without first giving focus to the spinner input field, the spinner does not fire the change event on blur of the input field. This does not occur in Firefox or Chrome.

Further investigation reveals that a second focus event fires within the spinner in IE after all normal processing for the spin action has finished. This second focus event does not occur if the user has already placed focus on the input field.

The second focus event means that the stored previous value is updated twice during the first spin, so on blur of the input the check on whether the current value differs from the previous value always fails, incorrectly, and the change event is not fired.