In Flagg Energy Dev. Corp. v. Gen. Motors Corp. 235 Ga. App. 540 (509 SE2d 399) (1998), the plaintiffs purchased turbine engines from one company that were manufactured by General Motors ("GM"). After becoming dissatisfied with the engines, the plaintiffs entered a settlement agreement with GM; and as a part of the settlement, GM assumed all of the duties of the seller under the original purchase order. The plaintiffs filed an action in Connecticut against GM based upon the terms of the purchase order, and then filed a second action in Georgia, alleging a breach of the settlement agreement. The Court concluded that the subject matter in both actions involved GM's duties under the settlement agreement; therefore, res judicata applied to bar the plaintiffs' Georgia claim. Id. at 542-543 (1).