Internet Explorer Settings

I'm working on an application which we're trying to use some basic Atlas features in. When running our application in Visual Studio 2005 and when we access it on the production IIS server from our computers everything works fine. The problem is our clients have hardened systems (we can't even see what options are enabled/disabled in Internet Explorer) and when they try to use our application, the Atlas does not work, it does a full post-back/refresh. I also test the Atlas Control Toolkit demo site on their system and the CascadingDropDown controls didn't even populate. Has anyone seen this before or have any idea what Internet Explorer options need to be enabled in order for Atlas to work correctly? I also don't think it's an Ajax problem because Telerik controls work fine on their system, Atlas is the only problem. Thanks a lot!

Thanks,

RobBump...