Flash site not displaying in IE

Hi there
I have developed a flash site and am viewing it thru IE 6.0.2900.2180 which works fine. THe problem is that some other peole who have tested the site for me cannot see it…it won’t display and just times out. They are using IE version 6.0.2800.1106. Both these versions of IE should have flash player 7. So i cannot understand why they cannot see the site. The site is an internal intranet site so i cannot provide the url in this forum. Any advice would be GREATLY appreciated!