DISHWASHER DISPENSER DRAWER NOT WORKING PROPERLY?

I'm having the same problem as this - my diplomatic integrated dishwasher is not always dispensing the tablet.

I've isolated the problem, which is that the pipe at the bottom of the machine keeps popping out so the water pressure from the jets on the spinner is limited.

However, I cannot work out how to stop the pipe popping out.

Can anyone help with this? Would be much appreciated.

Matt B
December 2008