"Leave a Reply" doesn't display

For my site: http://chs78.skycor.net , the "Leave a Reply" section doesn't display on any of my pages or posts. I tried disabling all of my plugins and the comments section still didn't display. I believe that I have all the settings under "Discussion" properly set to enable comments. For my test site: http://fun.skycor.net , the comments section does appear. I've compared all the things that I can think of between the two sites and haven't discovered why they behave differently.
I exported the montezuma settings from chs78.skycor.net and imported them into fun.skycor.net and the comments section disappeared. So it's definitely something I've done to the Montezuma configuration on chs78.skycor.net that has made the comments section disappear. But what?