I just bought a used titanium Seamaster Professional Chronometer from eBay...it looks great and keeps time accurately, but the hour hand for the chronograph feature won't stop! It keeps turning even when the chrono is not running. When I press the reset button it zeros out along with the second hand, but then starts running again. Is this normal? Is this a well known fault which can be easily fixed by an Omega AD? The watch came with an original box but no signed warranty card, only a warranty certificate with a serial number on it.