I'm horrid about answering e-mail sometimes, and when I don't answer soon after receiving a message, it tends to get left unanswered for a very long time indeed. I've spent the better part of the day today going back through my backlog of unanswered messags and clearing it out. At some point, I had to decide unanswered messages older than a certain date aren't going to get answered. So if you wrote me six months ago and never got a reply, you might want to try again. I'll try to do a better job answering my messages going forward.
Also, just for the record, I read everything, even if I don't answer. Always have. Your feedback is seen and appreciated, even if I'm lousy about communicating that fact.