In order to make use of your Bluetooth mouse you need to do the following:

# aptitude install bluetooth

$ grep HIDD /etc/default/bluetooth
############ HIDD
# HIDD_ENABLED to 1.
HIDD_ENABLED=1
HIDD_OPTIONS="--master --server"
# HIDD_OPTIONS="-i AA:BB:CC:DD:EE:FF --server"

# /etc/init.d/bluetooth restart
Restarting bluetooth: hidd hcid sdpd hidd rfcomm.

# hidd --search