Hi sorry to hear about your problem but I might just have the answer. Some time when placing your drainage pipe from the washing machine it is easy to push a the pipe to far into the outlet pipe for the drain. This can cause a syphening effect which drains you machine as it fills. Simply try and pull your machine drainage pipe back out of the outlet pipe. You need no more than 20 cm of Drainage pipe in the outlet to allow the machine to drain and stop any spillage. Hope this helps, good luck.
Iain
January 2010