When you launch a Citrix app you find that the process of logging hangs for upto 20 seconds whilst applying internet branding policy.
Cause
Internet Explorer 7 introduced an error that causes this problem to occur; the error occurs as a result of command line parameters that are parsed by Internet Explorer 7.
If you are running Windows 2003 server, install the below hotfix to a test Citrix server if you have one available before applying to all servers.