Wireless & XP

I am having an issue setting up a wireless network. I have set up wireless repeater to extend to 2 distant machines. The furthest machine, running 98, is OK but the closer machine running XP, seems to be dropping the wireless connection. It will actually remove it from ‘available wireless connections’. Is there possibly a setting in XP that is helping to cause this? I plan to try re-installing the wireless PCI cards driver.