QCS is synchronizing without errors, and the stub objects are being created successfully. However, the stub objects do not appear in the GAL in Outlook - they are only visible under address list "All Users".
This may be related to the LDAP query being used by your GAL.
Examine the Global Address List in Exchange. LDAP query is used to determine which users are placed in the GAL. Please check to make sure this LDAP query includes the QCS stub objects. You can click the "preview" button, or run the LDAP query using LDP.exe or ADSIedit, etc. Picture below has an example:
