I have a code in my project to open a calendar in child window on click of a link in home page. The calendar has 2 drop downs (for month and year). The calendar drop down is working fine in all browser except IE9.
I think the first step in troubleshooting this is to look at the actual generated HTML. In other words what is in that variable before you print it. Maybe there is a typo that some browsers are happy to ignore and others are not.