I've had similar problem with mine and it was down to a connection block in the wiring loom. There are 2 which could be the problem 1 is in the passenger side footwell and the other in the boot practically above/behind the nearside wheelarch. Basically you have to find the wire that feeds the heated windscreen (from what I recall it was white with some stripe) and just splice in another wire bypassing the connector.
Andy, March 2009
