You say you left 'damp' clothes in it - I wonder if they were damp enough to drip - in which case perhaps water has got onto some contacts and has created a slight earth leakage hence it trips when you try and use it. I would disconnect it, pull it out and remove the back cover and then try and dry out the inside- with a cloth if it is still visibly wet - or by directing a fan heater at the machine on a low heat setting to get it completely dried out. When you've done that, reassemble and try again.
Richard, January 2009