Page being loaded twice

I'm developing a ASP.NET 4.0 application with the Patterns and Practices MVP pattern. When I was debugging today I noticed that my page load was being fired twice. When I turned on Fiddler (A HTTP Traffic Monitoring Tool) I was able to pinpoint that my Page was actually being downloaded twice. I'm wondering if anyone has any idea what migh开发者_高级运维t be causing this?

Make sure you don't have any image tags with "#" for source <img src="#"/>

Also, img tags with no "src" attribute or pointing to a non-existing file can strangly trigger the Page Load event.