Recently I came across a problem with comments moderation. I didn’t want to have comments on a blog moderated, so I have turned it off in a discussion settings in WordPress. But WordPress kept putting all new comments into the moderation queue.
The answer is an Akismet plugin, that was turned on but not initialized (no code generated). Apparently Akismet in that state treat all comments as suspicious and overrides WordPress by putting them to moderation queue.
Disabling Akismet plugin finally turned the moderation off.