NON POLITICAL - Television Comment

I just saw a preview for the upcoming episode of "Heroes" and I just have  to vent my disgust at what I call "filler episodes."  If you have a show and there's a very engaging story arc DO NOT INTERRUPT IT for some mundane flashback kind of episode where you can reveal some things about your characters that you hadn't thought of in the first 2 seasons of your show.  All the shows do it and I don't understand why other than an excuse to let the writer's illiterate nephews and nieces write  an episode of their favorite show.