Just had the very same problem with my neighbours cooker - exact same model. After inspecting the individual hob switches I was able to see that the 'short', which is causing the 'trip', is caused by one of the hob switches. In fact a second switch was close to causing the same problem. The problem is that one or possibly more of the brass connectors in the switch, which makes or breaks the power circuit has 'welded' itself in the 'make' position causing the short. Poor design and poor quality materials, as I have already said the second switch is near to causing the same problem. Can only suggest replacing the 'switch' - ouch! Prices for this piece of cheap plastic are extortionate! I can give instructions on how / where to check - need to take apart lid of cooker to check.
Stephen Connor SW Scotland, March 2008