Vista Business: Bluetooth Hands-Free Breaking Skype

I just got my laptop with Vista Business. As an experiment, I paired a
Bluetooth headset with the laptop, to see if it worked; it did. The problem
came later, when I went out with the laptop and tried to call someone on
Skype, without having brought the Bluetooth headset with me - I got a message
on the taskbar saying that a program was trying to use Bluetooth hands-free,
and to connect the headset (which I didn't have). I uninstalled the headset
from Bluetooth, but that didn't make the message go away. There's a
check-mark on the Bluetooth Devices "sound" tab, saying "Control Skype(TM)
calls using a hands-free device", which I would un-check, except that with
the device un-installed, the check-mark is grayed-out and locked in the
checked position.

How do I turn off Vista's insistence on syncing up with a headset that's no
longer installed?