I had this problem when working on a web project (C# ASP .Net). The problem was, the page was loading twice for every request made. This was happening only for GET requests. And it was working fine for POST requests. After doing a long research on it I found the solution in the below blog post. Hope this will help you too.

http://cherupally.blogspot.com/2009/05/web-page-loading-twice-problem.html

This post was moved to a new location

http://cherupally.blogspot.com/2009/04/hyper-text-tranfer-protocol.html