UBB.threads PHP Forum Software Community Forums UBB.threads 7 Version 7 Support How do you locate (and delete) posts by users who now are unregistered?

Also when they are found as the first poster, how can I delete the first post and leave the rest (software set or won't let me delete that post as it has replies) or how can I move all posts AT ONCE to be a seperate thread (without having to move each and every reply one by one).