I got the toshiba stack from here http://aps2.toshiba-tro.de/bluetooth/index.php?page=download-toshiba and it worked on my cheap generic bluetooth adapter. It was a trial version and auto-connect didn't work for me but hopefully this will help you. I'm getting the same authentication error as you so if you figure this out then please let us all know. I'm thinking this is a problem with the bluetooth adapter and I'm close to just buying another one.
OS: Windows 7 x64
CPU: i7 3770k
RAM: 8GB
GPU: Asus GTX670-DC2
Skyward Sword Wiimote Plus RVL-CNT-01 (LMA-RVL-WR/M-C2)
Cheap USB Bluetooth dongle
CPU: i7 3770k
RAM: 8GB
GPU: Asus GTX670-DC2
Skyward Sword Wiimote Plus RVL-CNT-01 (LMA-RVL-WR/M-C2)
Cheap USB Bluetooth dongle
