[Plugin: WP Super Cache] Not sure if it’s working

I’ve installed the plugin and there doesn’t seem to be any problem with it, but I can’t tell if it’s really working. For example, neither <!– super cache –> or <!– super cache gz –> shows up at the end of the pages. The last item is only <!– Dynamic Page Served (once) in 1.545 seconds –>.

Secondly, my favicon stopped showing up. 😛

Any help you guys could offer?

Update: <!– super cache –> shows up now, but only when I’m not logged into WordPress.

Update 2: Odd, that line seems to disappear when I’m logged into WP using Firefox 3, Chrome or IE7…

Ahem..update 3: Tried with a friend of mine. She saw the <!– super cache –> as well, and she has never been logged into the page.

Does that mean everything is working as it should? 😛