Thanks for the reply, seems however this was caused by the wireless dongle driver.
Uninstalled, and reinstalled the USB wireless network device, and all has come back to 'normal'
I did see something similar posted elsewhere, that usb wireless devices have issues with XP SP3 occasionally, but thought that ipconfig would still give the localhost info?! Apparently not!!
Anywho, thanks again for checking my post, chalk this up to <more> experience