Some Java applications (such as Google Maps) won’t work in IE8, even when Java is installed correctly.
A possible cause is that the security level of your Internet zone is set to High. This will block the functionality of the Java applications.
Solution 1: Move the website to the Trusted sites zone. In most cases this zone has a lower security level then ‘High’.
Solution 2: Change the security level of the Internet zone to a level that is lower then ‘High’. This can of course be set through Group Policy under ‘User Configuration / Internet Explorer maintenance’ or through Group Policy preferences (Windows Server 2008).