hotpoint wma74?

My WMA74 will not complete a full wash cycle unless its on a fast wash or if the drum is empty. When cloths are placed in the machine and any program is selected it will wash as normal but will stop/get stuck before the rinse/spin. The drum it self moves round fine. If I then select a rinse/spin it will still not work. the only time it will work as it should is on a fast wash or when the drum is empty ??? Anyone know the reason or a fix for this problem ??? My machine is about 6 years old and never had any problems before.