Menu disappears briefly in IE on page change

Hello,

My website is written in PHP and I tried all possible header cache settings but couldn't solve this one out:

The website has a menu on top with several buttons navigating to subpages. Each of them has the same menu on top.

The problem is that when a button is clicked and IE navigates to another page - the whole page, together with the menu, disappears
for 1 second until new one is displayed (with the same menu). What I'm trying to achieve is that the menu doesn't disappear when IE
navigates to a new page.

If I use Firefox or Opera, the top menu always stays "static" and does not disappear. I assume the browser does not update the page
until the new one is loaded. What's interesting is that when I use IE to browse the website from my local machine (with Apache) the
menu doesn't disappear either. The problem is only when the website is retrieved from web and IE is used for browsing.

Any thoughts would be greatly appreciated...