Nav Bar background image doesn't show upon opening page

[terryn.ohio]

Our web page nav bar was built using Visual QuickMenu 7, we could never get the CSS to work right unless It was put into each page. I'd really like to direct all pages to a single external CSS file, but when I do that - the "qm0" background gradient doesn't show up until some part of the nav bar is mouse-clicked on. Any suggestions?