I guess you've figured this one out for yourself now but I came across your question while this same problem was driving me mad. So here's the answer for the next person!
Your machine has not finished its cycle from the last use - as it is a built in appliance, this is not always obvious! It needs to finish the dry cycle - simply shut the door and wait. Nothing will appear to happen but go away, have a cup of tea and when you return everything will be back to normal!
Phew - no huge repair bill! :-)
Simon, September 2009
