DBW15 sump filling with water and causing fault?

Hi,
I had the E4 message so done all the things suggest(mop out salt dispenser/sump). This cleared the error message but as soon as the dishwasher starts to fill, the water is coming out of the overflow pipe set at the front of the washer. Is the drain pump knackered, or does somebody have a magic remedy.
Thanks:¬)

joeant
November 2010