Sometimes the Blueooth radio goes a little wacky on the iPAQ. If the PC and GPS can't speak to the iPAQ any more, I'd try rebooting (soft restting) the iPAQ then hard reseting the iPAQ to erase it and start fresh. Be sure to make a backup of your iPAQ before hard reseting it though.
-------------------- Lisa Gade Editor in Chief, MobileTechReview