Hello Deepak,
Did you set "gw/acl_mode = 0" at the gateway where the program is being registered?
This would be the gateway indicated at the "gateway options" of the SM59 destination.
If the "gateway options" are blank, the parameter has to be set on all instances of the SAP system where the destination exists.
In addition, if you changed the parameter dynamically (e.g., transaction RZ11), you have to de-register and re-register the program (as informed at the WIKI, when it talks about changes to the reginfo file).
Regards,
Isaías