I own two of these watches. One of them - no problem. The other (slightly older) has developed a problem where the home position of the second hand needs to be brought forward anything up to 10s a day. This happens irrespective of whether it has picked up the overnight time signal and I have just put new batteries in both of them with no change. I have asked Casio and they just say 'send it back for repair' but as I have two I don't really want to pay to get a 'new' one, I'd rather put that money towards a different watch.

Does anyone have any ideas of what might be causing this? I thought the time-keeping circuit must be out by several seconds a day but when I reset the second hand to '12' it does then go to the accurate time, so there seems to be some lag that builds up between the time-keeping circuit and the actual second hand. I can't offer much in return for the answer apart from some advice on dentistry if you want some! Thanks.