IE Fun Fact: "disabled" not supported for <option>s

Select, Option, Disabled And The JavaScript Solution: “As I mentioned recently, there is a bug in Internet Explorer that stops you from disabling options in a select/dropdown element.”

Yes, that’s right. You cannot disable a menu item in a <select> box in IE6 or IE7. The above post goes on to list some failed attempts at a solution before coming up with something that works, involving listening to onchange and correcting selections of disabled items.

Hat tip to Jason for getting bit by this.