Thanks for all the readers. I managed to resolve my problem.
The issue was with the LDAP filter. I discovered that when I created a new role with the minimum permissions for doing the synchro.
My personal conclusion...the debug mmode was useless as the ouput.
Hey Johan, could you please provide me the correct LDAP filter syntax which you used to fix the issue, I am having the similar type of issue at client site, thanks in advance.