Lingering bg in dropdown menu

[newlyned2]

In IE, I notice that there is a lingering background in my drop-down menu under SCHOOL INFO/CALENDAR and also the other submenu item. It seems to happen when hovering across the top... inconsistently. Does anyone have any ideas why this is happening?

http://www.site-setter.com/haynes/index.html

Thanks in advance!
Natalie

[calskin]

Which IE? I'm not seeing it happen.