I have a Logitech DiNovo Mini (combined keyboard & touchpad), which at first worked just fine on my Gentoo laptop, Asus G50V, using the laptop's built-in bluetooth adapter, Bluez major version 4 (4.101-r5 today), and manual connection. Then I tried to connect the DiNovo to other devices, both without and with the USB-bluetooth-dongle that came with the DiNovo. Then I wanted it back to my laptop. There was a time when it worked only if I temporarily removed the battery from DiNovo. In the end, after several weeks if not months, it did not work anymore, at all. Blindly poking around, I now found how to fix it.