I have just had a DV90T8240SH delivered and it is making a knocking sound (with associated shaking) as the drum rotates - even when the drum is empty. If I rotate the drum by hand I can feel that it is not smooth but has a 'start-stop' feel to it. These are at regular angular intervals and there are several per revolution of the drum. I can't be absolutely sure it is a fault but it is worrying me and feels wrong. I think I should probably return it as it was only delivered today but wonder if anyone else has this experience. Any thoughts anyone?