I have three battery version. It works with n900 using non-stock kernel and hidd-apple kernel module. It is PITA to pair with n900.

With instructions mentioned in link above and additional fiddling with simultaneous hidd --search plus pairing I got it paired without blinking led and N9 shows it connected. However, it is not working. Quite similar like N900 without hidd-apple. N9 don't have hidd-apple.