Indesit D41 Dishwasher?

when switched on, the machine starts as normal but wthin a couple of minutes a lot of water floods the baseplate and cuts out the machine via the float switch. There aren't any obvious leak paths, other than the overflow tube. I've dried it a couple of times but it repeats the problem. The speed suggests that the solenoid valve opens but the water goes straight into the baseplate.
Any ideas please?

John Boyle
March 2010