<p>When using Fiddler to monitor HTTP Requests &amp; Responses in Internet Explorer it ignores all traffic directed to <a href="http://localhost" rel="noreferrer">http://localhost</a>.</p>

To get Fiddler to capture traffic when you are debugging on local host, after you hit F5 to begin degugging change the address so that localhost has a "." after it.
For instance, you start debugging and the you have the following URL in the Address bar:
http://localhost:49573/Default.aspx
Change it to:
http://localhost.:49573/Default.aspx
Hit enter and Fidder will start picking up your traffic.