Indesit washing machine dial keeps turning?

Hi - my 1 year old Indesit WD101 has developed a fault, which appears to be a quite common one. When washing starts, the dial keeps turning. I've opened the filter and not found any artefacts and have run the 'reset' a few times, but to no good.

What's weird is this - if I hand-fill the drum with water (cold or hot) at the start of a program, the machine runs a whole cycle until it comes to the rinse, when the dial starts turning again. Is this a water pressure problem? The machine appears to have no faults (I took it half-apart yesterday to check); all the pipes appear fine. I even thought it may be a thermostat problem, but the fact it works with cold and hot water suggests otherwise.

Any ideas? (PS yes - Indesit are crap, I now know...).

Thanks in advance.