Portion of iRule not being processed

This is incredibly confusing - if I change the switch statement to look like the below - going to this URI with a capital C works....however, now going to this uri with a lowercase c breaks. It used to be the other way around. Something is funky as far as the case.

"c=*" {
               log local0. "Query string of URI [HTTP::uri] is [URI::query [HTTP::uri]]"
               HTTP::redirect "http://newforum.newdomain.com/default.aspx?g=forum&c=[URI::query [HTTP::uri] C]"
               return
            }