I had the same problem as you only my machine is a Hotpoint WM76. It turned out to be the drum spider had cracked and then split right across on one of the legs. Then again if you had the same fault, surely the engineer would have seen this when he was changing the bearings.
I got Hotpoint out to it under the 5 year parts guarantee. It only cost me £90 all in.
Might it not be a coin trapped between the stainless wash drum and the outer plastic drum?
pappyon
January 2005