You are right angelus71, but...
angelus71 wrote:If you have anything new to add to the subject, start a new topic and refer to the original.
I thing it would be better to follow the old post. If a topic ages and then somebody starts another one, it will age as well, then it will be something difficult to follow the topic, having to check two or tree old topics. Besides, if two guys have something to add in an old topic and they create a new topic each (each one not knowing about the other one), it will be more difficult to follow the topic (and if it's a hot topic it will grow like a three).
Of course, when I say a topic is old I mean one month or something, and if somebody has something to add it should be something worth to read or see, not just a "thanks", in that case, as you wrote, please don´t bring the dead upon the alive.