Zanussi JetSystem XC 1200 wash cycles taking hours - timer stuck?

My Zanussi Jet System XC 1200 (FJS 1225 W) is taking about 4 hours to do a 1hr 19m wash. It seems to get stuck and the "time until finish" doesn't change although the machine still appears to be working (drum rotating, making draining noises, etc). I've tried Pausing and moving it to the next stage (e.g. from II to Drain) manually then Starting but it just goes back into Pause. If I leave it to run through then it does eventually finish the wash ok but I don't imagine that situation is going to last! Is this something that I can fix?