jQuery datepicker's year dropdown pops open and closed in IE8

I'm seeing an issue in IE8 with the Year dropdown in a jQuery datepicker dialog. The dropdown opens when I click on it but only stays open until I release the mouse button. I've only verified it in IE8 and IE9 with compatibility mode enabled, and 开发者_运维问答it happens about 50% of the time I open it. There's a button nearby that seems to gain/lose focus at the same time as the dropdown list has this problem once in a while.

Google did not offer any help. What is happening here, and how do I fix it?

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A bug concerned with the year and month dropdowns was reported months ago but is still not fixed. It sounds similar to a question I answered a few months ago. Does that help?