I have the same problem with my Serial/USB Setup, except I wait until XP sees the adapter, then turn on my GPS. It first sees it as a 'serial port' then then the GPS comes up, XP doesnt look to see what it is, it just handles the data from it.
My biggest gripe about XP is that if I unplug my USB adapter while the GPS is turned on, I get that dreaded 'blue screen of death' and because its on the laptop, it kills the keyboard AND the power switch, so I have to unplug the power then flip the battery just so the thing will reset, REALLY annoying, needless to say it only took me a couple of times to learn my lesson
