Advertising your hub in a answering a question IMHO is bad form.
Probably OK to link to a picture or relevant site but to do it with the intent to get more traffic for you own hubs is in bad taste. Unless the author really did have the answer that you were looking for and created a hub about it than it is probably OK if it is not against the rules.
By the way it would not allow me to answer the question again either. Maybe they achieved God like status, and we have not got there yet. :)