If Jez's remedy doesn't cure the problem there might be a problem with the exhaust fan vent actuator (mounted on top of the fan motor).
Mike
October 2009
Remove the front cover by taking out the hex-head screws. With the front cover off you'll see a pipe which runs from the vent to where the detergent dispenser is (the bit where you put the tabs or powder in). This pipe just pulls off. Give it a good clean by running hot water through it and flexing it - you'll see all the gunge come out. Re-fit and screw it all back together. Hope this helps.
Jez
September 2009
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