And why did it work yesterday? That button used to center itself.
It turns out that I'm whack-o.
I have confirmed that the button never centered itself on the previous build (tested with someone who hadn't updated his WB today) and I'm sorry for wasting your time, Neil.
I still maintain that it should though......because I can't imagine that it would look good on many blinds riding high on the taskbar. Oh well. When unskinned, I get the vista button which gets me the result I want.