Oh, sorry, I just assumed it was some universal rule for all forums.
Other places make such a big fuss about bumping an old thread, I just don't get it.

True, I always fnd it strange when a topic moves to the top of a forum but nothing is posted.
I just let the topics age quietly (and frankly I consider the topic bumping feature nothing more than an invitation for topic necromancy, so I always disable it).