Citrix – opeing PDF

we are running in a Citrix setting. From with in IE we from time to time have to open PDF files. For what ever reason there is one site we go to and the PDF’s will not launch. When you try to launch it or actually some doc files aswell they don’t have a file association to them. Other sites are fine!. If I install Adobe Reader on my local system it will launch using it. We do have redirection enabled and as I said it does work with other sites.

Any idess?