Bosch Classixx Dishwasher - Diaphram Problem?

Hi,

I have just been looking at the bosch questions related to the "float valve" problems. I have done exactly what they suggest, and the float valve was covered in gunk, so after cleaning everything out and putting it back, I am now finding that the "diaphram" (the yellow part in the pressure chamber) isnt expanding and clicking the top switch in order to start the cycle, so the machine now keeps filling.

Could there be a reason for this? Would it be possible to post a pic? I think i might be missing a gromit as I only have 1 on the pressure chamber and I think that I should have 2.

Many Thanks
Matt