I am using Fiddler to monitor HTTP requests for a web app that uses frames
for navigation system and content. I am seeing that the content frame is
making GET requests for all files as I navigate back and forth between two
pages. If I use BACK history, though, the cache IS used.

This makes for a slow user experience because the navigation tree (different
frame) will load the specific page into the content frame with
location.href, and the server will be hit for all files each time.

IE works fine with this. Is this by design or a bug in FF?