Serviceprogram and BNDDIR Parameter

Hello,
we use a SINGLE binding directory for every program.
This binding directory lists the names of modules and service
programs we might need when creating programs or other
service programs.

Binding Directory A
        - S1    *SRVPGM
        - S2    *SRVPGM
        - S3    *SRVPGM

Our problem is if there is a service program S1 with
several procedures including the EXPORT keyword and
our single binding directory A on the BNDDIR parameter.

When we try to create the service program I get the error:
CPD5D03:  Definition supplied multiple times for symbol ....

How can we solve this problem?

If we set the parameter OPTIONS in the CRTSRVPGM or
UPDSRVPGM command to *DUPPROC the program is then
created without error. But it makes it impossible to defend
against problems caused by someone creating a completely
different procedure with the same name as another.

Thanks,
Alexander Brand