Jon
The funny thing with the delicates wash on the Zanussi is that if you fill it with a big load of blacks or whatever the machine doesn't `refill' to the orginal level after the machine has agitated a couple of times to saturate the clothes so actually the water level can dip to almost synthetics wash level. Could this be the issue?
FWIW my Zanussi fills to about that level on delicates but only stays that level with a small / non absorbent load
Nick