Trouble with rewrite rule

We have weekly newsletters that send out emails, and in these emails we have links to some case studies.

An example of a link is:

http://www.oursite.org/info.aspx?id=67727

This link is then redirected from another system to:

http://oursite.org/articles/2009/11/01/article-name-here.aspx

Our F5 contains an iRule that is supposed to strip the www first before it is then redirected. The stripping of the www in this case does not work.

The following iRule DOES work for all links outside of our newsletter emails, for example: http://www.oursite.org/somelink.aspx WILL strip the www and rewrite to http://oursite.org

If I copy and paste http://www.oursite.org/info.aspx?id=67727 into a browser and manually take out the www, the link works.

NOTE: The rewrite DOES work in Chrome and Firefox, but NOT IE.

Is there something wrong with the way that I am trying to catch www.oursite.org in the following iRule? Why would only IE not rewrite correctly?

 
 when HTTP_REQUEST {   
      if { ([HTTP::host] eq "www.oursite.org") } {   
          switch -glob [HTTP::host] {   
               "/" { HTTP::redirect "http://oursite.org" }   
               default {  HTTP::redirect "http://oursite.org[HTTP::uri]" }  
          }   
      }   
  }