When you attempt to install a Bluetooth device, it is either NOT discovered, or it stops working (and isn't discovered again)?
If you plugged the Bluetooth radio directly into the USB 2.0 root hub, the USB controller falls back to USB 1.1 support and you don't experience this behavior.
When you plug the Bluetooth radio into a downstream USB 2.0 hub, it is running as a USB 2.0 controller and the device is NOT recognized.
NOTE: You must have SP1 installed to have USB 2.0 support.
NOTE: The same behavior will occur on port replicators, where the secondary USB ports on the replicator are downstream USB 2.0 hubs.
To resolve this issue, plug the Bluetooth radio directly into the USB 2.0 root hub, or use a USB 1.1 hub/controller.
NOTE: Undock the portable computer and plug the transceiver directly into the portable computer.