As Digibloke said your module needs a new quartz crystal, its a ten minute job if you are competent with a soldering iron. If you have a local electronics store that sells components I'am sure they'll have the 32,768Hz quartz crystal you need to repair your watch.
This is what to look for -
http://cgi.ebay.co.uk/NEW-QUARTZ-CRYSTALS-32-768-KHZ_W0QQitemZ150096755920QQihZ005QQcategoryZ7286QQrdZ1QQssPageNameZWD1VQQcmdZViewItem
When you remove the module from the watch take a small jewellers screwdriver and gently prise apart the module along the join, you’ll have seen the sticker with NS on it this is where the original crystal sits, its held in a silicon type substance just keep gently prising the two halves apart and the crystal will come away and leave the sticker on bottom of the module, you can peel it off if you want but it looks original if left alone.
Next step is to replace the quartz itself , don’t use a high temperature soldering iron as its not good idea to overheat the module too much just a quick de-solder and the old crystals off. Its just a matter of soldering on the new one and bending it flat to fit back inside the groove then re-build the module and test it back in the watch.
You should now have a module that’ll keep good time...