Can you confirm that the public card, i.e. the one that you are trying to connect to, is the top binding card.
To find this, go to the machine that the alert repository is on and go to Network Connecitons > Advanced (along top menu bar) > Advanced Settings.
SQL Response automatically looks for the top card, therefore if the card that you are connecting to isn't at the top then you will have issues.
I hope this helps.