using bluetooth adapter in multiboot (Vista + XP) environment

Hello,
I can't solve this problem: I have multiboot with Vista and XP installed
(testing software a lot). I have problem with Bluetooth in this
environment - device paired in Vista doesn't work in XP until re-paired and
vice versa. Annoying

I thought both computer (BT adapter) and peripheral check pairing status
only by BT addresses once paired but it seems to be more complicated.

If someone figured out how to have one device (such as mobile phone) paired
and working seamlessly with both OSes please let me know.

Thanks

Miroslav