If you attempt to record HTTP traffic for a web application in IE you will probably find that requests originating in secondary popup windows and tabs will not be recorded. This behavior is due to the way that IE creates a new process for each tab and popup window. HttpWatch works at the process level so you would need to open HttpWatch in each window/tab and click on Record.
A simple way around this is to use the original IE 7 process model. You could do that by creating a registry value called TabProcGrowth and setting it to zero. There’s more about this setting in the following blog post:
http://blog.httpwatch.com/2009/04/07/seven-things-you-should-known-about-ie-8/