OK, so...the Massoth system is operational and the RhB GE 4/4ii performing well with its sound decoder. But, there seems to be a problem with the steam engine (LGB 20752). All seemed OK when I tested it in the shop but when I put it onto my track the only sound I get is the long whistle...and often it just continues and continues and you can't stop it! Any ideas as to what the sound problem might be would be much appreciated. Brand new, no CV's changed, loco address is still 3 as set in the factory. The loco runs and the lights work incidentally, just the sound.