AJAX ComboBox with Postback = True and moving down in IIS 7 with IE 7, 8 and 9

Hi All,

I have developed an ASP.NET 4.0 site with AJAX ComboBox controls. The Postback property is set to True. When I run and test the project in VS.NET 2010 everything is working fine in IE 7, 8 and 9. When I deployed the site on the server with IIS 7.0 and run the default page in IE 7, 8 and 9 all the AJAX ComboBox controls moved down. Do I need to change any property to fix this problem? This does not appear in Mozilla and Chrome!

Thank you for your help.