Malpassi Filter/Reg Diaphragm

Hi folks,

          I am having a few issues at the minute with fuel supply through my Malpassi filter king regulator to a set of twin 40 Weber DCOE's.  When I replaced the filter, I inadvertently removed the whole lid and the diaphragm fell out.

Can someone confirm which way round the diaphragm should be fitted as it is not clear from the manufacturer's drawing.  I put it back in they way I thought seemed logical, but maybe I got it wrong.  I'm only getting a trickle of fuel into the glass bowl and then it stops with only about 1cm of fuel in the bottom.  Pretty sure the pump is the problem, but want to make sure I haven't made a problem with the diaphragm.

Cheers