Same here. Took it to a repair shop. I'd been decorating and it turns out the filter can't handle the dust. They entered the motor and it's broken. Repair shop said he sees loads with the same problem - he'd never buy one. Said they used to be good, but their filters aren't up to it. Replacement motor will cost £85!!! Given I only bought the unit for £160, take off retail margin and wholesale margin, I reckon they make these and ship them to the retailer for under £75, so to charge £85 for a spare part is a rip off.
I'd much rather repair than throw the whole unit away - such a waste!
EHM, November 2009