Using secondary groups for sudo roles in AIX

Hi,
    We are using AIX 5.3 and using QAS 3.5. We have not tested "Quest SUDO" and so we are NOT using that as of now.

   We are finding that we cannot use sudo rules for secondary unix groups. It works only for Primary Unix group. Are we missing something here. Both Primary and secondary groups are Unix enabled and can been seen when we do a lsuser.

Thanks
Manohar