had the same problem,turn off electric from socket, not on/off switch! , undo all the screws around the edge inside door, outer metal drops down, inside control unit, undo 2 screws holding locking mech, push plastic clip back into opposite position, you will hear it click back into position, put back together, bit awkward screwing back, make sure control unit sits on 2 plastic lugs on door before lining up screw holes
mitchcav, December 2010