Vaio PCG GRT 380ZG W Lan Express miniPCI drivers XP Pro don't work

I bought a Vaio PCG GRT 380ZG with XP and the Lan Express miniPCI came
included. I upgraded to XP professional, the wireless connection seems
to hang. I updated the driver from Sony for the Lan Express miniPCI,
it does not work. I unistall the driver and installed many times in
different ways, safe mode, etc, at no avail. Sony service recomends
to re-image the laptop ... which I find very drastic.
Any suggestions? Does anybody knows who is the supplier of this driver
to Sony?

Thanks for any help on this!

David