I came across an interesting problem where some users despite having the right access rights could not able to connect to a web page where others could. It turns out that the users who could not connect where members of more active directory groups than the ones had access. The root problem is somewhere in the authentication/authorization of Active Directories. Since I don’t have access to the configuration of AD I could not address the root of the problem. Here is a work around for this problem...
http://www.nigelfindlater.com/KnowHow/PublicKnowHow/3801