I've not noticed any problems with XP and USB ports. I use all sorts of devices without problems. Including a Haicom GPS. I've stopped using Microsoft products, not because of problems with the GPS, but because they don't give directions and only update the position every 15 secs.
I'm now selling Infomap Navigator Europe bundled with a USB monitor for £124.99 +p&p. Have a look
here. A much better solution.