BT Wireless network card problem

I have two windows 98 pc's connected in adhoc mode via BT wireless network
adapters.
My problem is that quite often I have to unplug the adapters in order for
the pc's to boot up.
This usually happens when they get to the windows logo splash screen on
either machine.
Once the pc's are past the splash screen I can plug the adapter back in and
everything is ok.
This is starting to really bug me now.
I've reinstalled the adapter software a few times but that's hasn't done
anything.