Steve
I too have the same washer. Ours did this a while back. The problem with ours was the door catch wasn't seating correctly when closing the door making it difficult to open afterwards. I took the door off, spilt the door into two (just unscrew it is not difficult) and found the spring had slipped. I adjusted it to its original position and it has been fine since. Just take note where everything goes taking apart so that it fits back together again.
Hope this helps.
Scott
Scott McKenzie, August 2006