First Make sure that both units are not awaiting pin codes.
Secondly make sure bs3200 has been optioned corretly, if you only have the bv9 and bs3200 in the same room put the 3200 into aopt 0.
on beo 4 press and hold standby and list together until "add" is display in beo4's display then keep pressing list untill "option" is displayed then press go, then press "list" until "Aopt" is displayed, point beo4 at bs3200 and press "0", standby light should blink once.
If your using the bs3200 standalone and not connected via ml then press 2 instead of 0.