This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
In Internet Explorer, the back button causes the browser to look for the last page in the browser cache. One problem you might run into is that if you have code in your pages to tell the browser not to cache the page, the user could get a message "This page has expired".