Windows Vista idiot filter

I just bought a laptop with Windows Vista preinstalled. I’m trying to access a web site I find important to access. I’ve used this web site for about eight years now and I’m quite familiar with the people who make it. However, I can’t figure out how to convince Windows Vista that I trust it to install an ActiveX control even though it doesn’t. How do I disable this ‘feature’? I’ve added the web-site to my trusted zone and that hasn’t helped.