I have the exact same problem, with MacOS 10.7.5 on a MacMini with RemoteBuddy 1.2.3. I just ordered and received a Wiimote (Motion Plus).

Remote Buddy says pairing successful, but never connects. Then after about 10-15 seconds, a screen notice appears saying the Nintendo has disconnected.

In the console, the messages are : 
1/17/13 1:53:36.881 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 9 seconds 
1/17/13 1:54:34.479 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 9 seconds 
1/17/13 1:55:36.540 PM Remote Buddy: *** WARNING: Method selectRow:byExtendingSelection: in class GradientTableView is deprecated. It will be removed in a future release and should no longer be used. 
1/17/13 1:55:52.919 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 10 seconds 
1/17/13 2:00:21.376 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 10 seconds 
1/17/13 2:01:37.790 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 9 seconds 
1/17/13 2:02:11.652 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 9 seconds

I tried everything I could find in the forums. Using 1+2 or the red Sync button. Pressing them repeatedly.

I tried connecting using Apple's BlueTooth Setup Assistant. It finds the device but then says the device refuses pairing, console message: 
1/17/13 2:12:40.413 PM Bluetooth Setup Assistant: Pairing failed with 'Nintendo RVL-CNT-01-TR': error 0x5

I opened the Passcode Options and specified "Do not use a passcode with this device". It was able to pair, although the console says: 
1/17/13 2:12:45.992 PM Bluetooth Setup Assistant: skipping real pairing

It then appears as a connected device in Apple's Bluetooth menu, Remote Buddy sees it in the list of paired devices in its Preferences > Hardware pane, but it still does not see it as a connected Bluetooth Receiver in the Remote Buddy menu.

If I try to pair it at that point with Remote Buddy's Setup wizare, I get the following message:

"Preparing pairing... please wait..."

Console says: 
1/17/13 2:17:36.438 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 6 seconds 
1/17/13 2:17:43.654 PM com.apple.launchd: (com.iospirit.candelair.sync) Throttling respawn: Will start in 9 seconds

After about a minute, a screen notice comes up saying that "Nintendo... disconnected"

I have no idea what else I can try now.

Any ideas. Please help !

Thanks.