What is the problem when menu populating?

When i mouseover on the hyperlink ‘products’ menu in top, in my sitehttp://rfcables.org, the menu items and sub-items are populating from database… it is showing nice in mozilla but in IE at first time when we mouseover on it, it wont display any thing. At second time when we mouseover on it(without refresh page) it will dispaly nice…

What is the problem and how to fix it?

Thanking you…