As far as I recall, when this problem first aired, the cause was that 
Apple's Bluetooth Kit would not stop the Bluetooth inquiries Remote 
Buddy made at the time and wake up the machine again, as they timed out.

The latest release should contain a fix for this for sure, so I'm not 
sure what the source of the problem is this time. I'll try later. 
However, you'd help me a lot with the following info:

1) Is the remote control connected or disconnected while you attemp 
it to sleep?

2) Does the problem also occur when RB is running, but the remote is 
not connected?

3) Does the problem also occur when RB is running, but you have 
Bluetooth turned off?

4) Which Mini are you using? The G4 based or the Intel based version?

Thanks!

Best regards, 
Felix