Hi Will, thank you very much for responding- I am getting a little desperate now as I am house sitting and it has done this while I am here (all I have been doing is winding the weights to start the clock again)..

I don't believe the weights have been switched- after posting here I took each one off and underneath it had stickers that said left, center and right. I tried putting a very slight weight on the center one and the little seconds hand moved again, but the clock still stops after a bit. I just got up this morning (my time) and all I did was start the pendulum off again and the seconds hand moved immediately as it should (this has not happened since the problem started) so I'm wondering if I could have somehow wound it up too much. I was instructed by the owner to guide the center weight up as I wind it as it is the heaviest and thats what I had been doing. I am hoping this problem has been somewhat fixed as I am getting a little headway- however if you can provide any other hints or info it would be greatly appreciated. I am just hoping the clock doesn't stop now!

Please excuse any late reply as I am off to work but will respond here as soon as I can

Thanks again for your response
-Chris

Thanks for the reply, I will take that on board- though she never said not to wind one till the key stops :/ Ah well I will just have to wait and see I guess.. Thanks