Drop down scroll bar disappears in IE7/8/9

I know this isn't a module bug, but the drop down's scroll bar in IE7/8/9 was broken. When clicked on it the drop down would disappear.

This has been fixed: https://github.com/drowe/DropKick/commit/f77a0ba20ade6dccee3697b96cd027a...

Just a heads up in case anybody else has the problem and came here first.