We have a Panasonic breadmaker that has worked brilliantly for a year or so. Now suddenly we've produced a series of disasters. The bread either over rises then collapses, leaving a sort of V shaped top, or only rises a bit, producing a sort of slighly soft brick. We've tried everything we can think of, adjusting the recipe according to the trouble shooting section of the book - being super careful with measurements, buying all fresh ingredients - but no luck. Could there be something wrong with the machine? Can't imagine what, because it still seems to heat and time properly - any ideas anyone?