Had the same sort of problem, but when i cleaned out the trap / pump at the front of the machine ( located behind the kick plate) I managed to get some bits of kit kat wrapper, stringy plastic and about £1.40 in change. Thought that was it but theres a small opening to the left hand side inside the trap hole. ( this is where all the gunk gets from the machine to the trap) on probing in there i managed to get another £2.10 which was backed up the pipe and would have jammed the pump again when the water was turned on. It might just be a case of having another look to ensure the trap is cleaned out properly. ( I had to lift the machine on its side to get the stuff to fall out with a couple of gentle taps on the outside of the machine to assist gravity with the job. Machine now working fine!!
Tony D,, October 2011