All, I read several posts on this forum on a rattling 240m pump. Unfortunately after a week of use, mine started to rattle as well. What strikes me as odd is that the pump is running at max rpms all the time (2800 rpm), and that I cannot change the speed no matter where I plug the pump connector in. I read in a few posts that it should run comfortably at 1400 rpm... i tried ... but it wont run slower. Any clue's? Should I return it/Xchange it for a new one? Thanks... Ben.