Ah Kath... How to explain muffining... You know Lisa's Flippersteps story? You know that there are posts after the chapters expressing the readers' thoughts... But Lisa's away for the rest of July and no more story will get posted till she returns. And yet, people are posting in that thread? Well, what those posts are are just fluff which add not much to the real value of the thread. Just pointless speculation, rambling, pointing out other things to other people and the such. When that thends to happen with any given thread, we say it's being muffined.
Another good example is what's happened in the Fraggle Rock Film thread.
Hope this helps explain. Oh, and here...
Have a muffin.