zanussi dishasher model DWS909?

there is a seal at the back of the top basket where the water goes down the top spray arm duct.Is this OK?
Block the holes in the bottom spray arm and see if the top gets more pressure and rotates.don't understand it really as top and bottom arms are link without any restrictions.if you are running the dishwasher with the door open you will have to push the top basket inwards to allow the water to go in to the top arm otherwise it will run down the back panel!!

ck
April 2011