Spam is a serious issue here because of our point system. I would guess that is probably a result of what gwoodruler said. Try to keep your posts relevant and a lot of 3-7 word posts are going to get flagged.
You are loosing points bcause of spam and many of your threads and comments might have been deleted. You are losing ranks because you are losing points and/or there are other members of AG that are getting more points then you.