A better change. If you use this conditional, it checks if the browser is IE, and it also checks to confirm that you *aren't* on the private message screen. So Merlin will bug the hell out of you until you click on the PM screen, but once you do he leaves you alone. I also changed the method to Merlin.think instead of Merlin.speak; now he just pops up a thinking box rather than voice.
Code:
<if condition="($bbuserinfo['pmunread']) AND (is_browser('ie')) AND (THIS_SCRIPT != 'private')">