I bought a generic bluetooth keyboard and I am trying to use it with a Mac mini using 10.6.8. The bluetooth setup sees "Bluetooth Keyboard" and connects to it. I enter the passcode on the keyboard, but after about 25 seconds it says "The pairing attempt was unsuccessful. This configuration of Mac OS X and Bluetooth software could be invalid or unsupported." If I watch the bluetooth control panel during this process, it says it is connected and paired as soon as I hit "return" but then disappears when I get the message. I already tried trashing com.apple.bluetooth.plist and restarting. I made sure nothing was on top of the Mac, and turned off the WiFi on my router, but nothing helps.
Update: Incase someone else has this problem, this is what I did. Use the keyboard system preferences button for a bluetooth keyboardsetup, instead of bluetooth device setup.