How can I fix my Hoover Softwave Dishwasher - leaking at start of cycle?

My Hoover Softwave Dishwasher - 12 years old - is leaking at the start of the washing cycle from the botton or sides of the unit. A few weeks ago it leaked at the end of the cycle but this was because it was blocked so I gave it a thorough cleaning and disconnected waste pipe etc and cleaned that. now it is leaking at the start of the cycle as soon as the machine is switched on - so wondering what is causing this