While somewhat related to point 8 (Follow up after getting an answer), my pet peeve is people who post about a problem they are having, not getting any response

While somewhat related to point 8 (Follow up after getting an answer), my pet peeve is people who post about a problem they are having, not getting any response, then a final "Oh, never mind, I figured it out". Auuggghhhh! The forums you use are a great resource not just for you but for others. A posted solution could help other people who are searching for the same question.