I have three forums running with 1.9.6.1 all with the same issue. I have multiple forums, but only a couple with any type of pre-moderation enabled on each one, mostly for admin posts and updates. However, people who have normal post access on forums with no moderation are having their posts captured intermittently and put into the moderation queue. I've seen this on at least two forums recently and I think it has happened on a third as well.

I verified that the forums in question had the pre-moderation check box unchecked and the people posting had full rights to post in that forum.

Try to disable the spam checking (Choose a SPAM Service for Automatically SPAM Checking) in the host settings.

Will do, and yes, I had it enabled on all forums. Hope that does it, thanks for the help!