If you view the demo of the Multiflex-3 template in IE9, you will see the pulldown menu doesn't work :x. Works fine in Firefox. Have been tearing my hair out trying to find a solution. SM2 doco gives me the heebie jeebies. Anyway, I found a fix here, though I have only tested it for a single-level drop down menu:
https://forum.WebsiteBaker.org/index.php/topic,9755.0.html (https://forum.websitebaker.org/index.php/topic,9755.0.html)
Many thanks to dadio for his solution.