Hi Faisal
Is LDAP the first system for authentication or the last user sync you ran? Check the GRACUSER table first to see if LDAP entries appear there.
I tested the user syncs in relation to GRACUSER and GRACUSERCONN a while back. I noticed the last connector ran for user sync contains entries in GRACUSER table and all subsequent systems for the user are in GRACUSERCONN. If you ran LDAP user sync last the users may be in the GRACUSER table.
Did you manually setup your Integration Framework for Connectors, Logical Systems, maintain connector settings (flag PSS for LDAP) or did you transport these?
I think you need to go through each configuration item between DEV and QA GRC and compare to see if there is a difference. If you have done this (do again in case you missed) and still no difference you may need to consider running a trace on the sync and see if your System Admin can trace the LDAP connection.
In addition, have you compared the SM59 and LDAP configuration for the LDAP connector between DEV and QA?
If still stuck, can you please post some screen shots for what you have checked?
Cheers
Colleen