Combobox issue

Combobox issue

I posted an question over the weekend about the following issue in IE7. I use the following code to change the font color on the drop down box. When the mouse enters I want the user to see black font but when the user exits and leaves the selection on the first entry, I want the font to be gray. This code works great in Firefox but in IE when I click in the box, the drop down list is displayed but as soon as I move the mouse to make a selection, the list collapses. Has anyone else seen this and is there a solution?

            $('.requiredCombo').bind('mouseenter', function(){
                $(this).css({'color':'black'});
            });
            $('.requiredCombo').bind('mouseleave', function(){
                if (this.selectedIndex == 0) {
                    $(this).css({'color':'#C0C0C0'});
                } else {
                    $(this).css({'color':'black'});
                }
            });

TIA,
John