zanussi washing machine (ZWI2125) not finishing cycle?

Hi hope someone might be able to help. everything seems to run ok on the machine through a wash until last spin after which it sticks on the 1 min timer and won't let me open door. Only way to correct fault seems to be to spin again and/or use empty water function. Sometimes have to do tis 2/3 times. Been like it for 1 month. Filter checked and powder draw checked.
Regards Susan