|thanks, but unfortunately neither has solved the problem.|
removing and replacing the battery made no difference; we have 1GB RAM inside the laptop, with the (original) 0.5GB installed in the slot on the back (sorry, I'm not that techinally experienced to know the correct terms!). have removed the 0.5GB RAM, but the laptop now just freezes with 'Shutting down...' showing on screen. I have to press and hold the power button to bring it back to life!
anything else i can try...?