Allow Comments switch – Gone (allow trackbacks also gone)

Does anybody know what would cause the Allow Comments function on pages and posts to disappear?

I deactivated each plugin one by one. After each deactivation, I reloaded the Edit Post page in a separate browser to see if the Allow Comments (and trackbacks and pinging) control would appear. It didn’t.

I deactivated each plugin one by one again. After each deactivation, I reloaded a published page to see if the Leave A Reply (for comments) would go away. It didn’t.

A few days ago, a comment (“Leave A Reply”) window was appearing on every page of the site I’m building.

We don’t want commenting yet.

So I disabled every setting under Settings, Discussion.

The commenting forms all went away.

But they came back.

And every setting under Settings, Discussion is still disabled.

So, to summarize, what we have is:

Presence of Leave A Reply box on published pages even though we don’t want it and every setting under Settings, Discussion is disabled.

Absence of Allow Comments (and trackbacks and pinging) control in Edit Post/Page, so can’t go in and disallow comments one by one on every post.

Sure hope someone has an idea for a solution.