put the numbers(vm ports) in a distributed hunt group 900(850).you have manual?
if you are unable to do that you also could use voice hunting. not sure of prog num (30 somthing). then use 81-89. i have found using disstributed hunt for the voice mail seems to clear up intermittant misbehavior by more than one stratagy that i have worked on. do you have other duties than getting this sys running? m