Some may argue that the navigation frame has to be loaded just once, but the fact is a navigation system embedded in the content page should not take as long to download anyway. Tests have been carried out and show that users hate sites which take ages to download. The average user can only keep his attention on a page for 10 seconds. As I've just said, not all browsers can show the brilliant frames that you have set up. Again, I put this to you plainly - people don't like scrolling pages which need not require scrolling.
People hate horizontal scrolling.
Most people use the 'Back' button more than any other button on their web browser. Frames make the 'Back' button useless. It doesn't, however, call up the URL of the last frame you viewed. So, if you press the Back button when you simply want to revisit a previously chosen frame, you'll find yourself further back than you meant to be. Another favourite browser feature people love to use is the 'Bookmark' feature.