I have a Western Digital external HD. I use FireWire to connect it to my MacBook and USB when I want to connect it to my PC. But, I find that when I eject my USB connection in Windows XP and unplug the hard drive, my BT Home Hub wireless internet cuts out and stops working. The PC cannot then connect back onto to the hub without having to restarting both the hub and PC.
It's really annoying and sometimes it seems to take more than one restart to get then connected to each other again!