Conn. Gen. Stat. § 50a-34: (Formerly Sec. 52-614). Grounds for nonrecognition.

(a) A foreign judgment is not conclusive if:

(1) The judgment was rendered under a system which does not provide impartial tribunals or procedures compatible with the requirements of due process of law;

(2) The foreign court did not have personal jurisdiction over the judgment debtor; or

(3) The foreign court did not have jurisdiction over the subject matter.

(b) A foreign judgment need not be recognized if:

(1) The judgment debtor in the proceedings in the foreign court did not receive notice of the proceedings in sufficient time to enable him to defend;

(2) The judgment was obtained by fraud;

(3) The cause of action on which the judgment is based is repugnant to the public policy of this state;

(4) The judgment conflicts with another final and conclusive judgment;

(5) The proceeding in the foreign court was contrary to an agreement between the parties under which the dispute in question was to be settled otherwise than by proceedings in that court; or

(6) In the case of jurisdiction based only on personal service, the foreign court was a seriously inconvenient forum for the trial of the action.