Stefan,
Thanks for the reminder, we're going to be getting our support up to date (today if I can believe my boss!).
As for your solution, it wasn't quite what I needed but I think I do have a way to do what I was trying to do:
-DefaultItemChanged won't work because I need the actionButton click to also toggle the highlighting
-using the menuItem_click won't quite work because by definition the mouse is over the button when clicking on it and leaving the button will trigger the IsMouseOver = false automatically
To solve this, I use the Tag property to store the toggle state. By subscribing to the mouseLeave event I can check the toggle state and reset IsMouseOver = true;
There is one more small problem, I'm working with the Office2010Silver theme. The CommandBarSplitButton IsMouseOver in this case just outlines the entire control. It seems that the split button highlight effects for this theme are split between whether the mouse is over the Action button or the Arrow button. However I can't find an ActionButton property on the button or in the element tree to simulate mouse over. (I'm fine with just highlighting the ActionButton if it means I don't need a custom theme).
Thanks,
Adam
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