I've downloaded v. 537.6+ of WebKit for Mac OS, and am running it on 10.8. (No programming here, just being a web developer looking for the WebKit web inspector.) Everything's fine, except the "Show page source" option in the Develop menu is grayed out when I'm on even the most, and I can't find any way to enable it. I"m very puzzled -- is there something else I need to do to get it enabled? Is there something else going on? Is this how it's supposed to be?
Developer Menu

The contextual menu:
