Acceptance of methods of payment other than those provided for by the contract waives the covenants of such contract with regard to such payment.1 An agreement to accept a draft unconditionally is waived by accepting a draft which is accepted conditionally.2 A provision that an agent would indorse notes taken by him for his principal is waived by accepting notes indorsed by him without recourse.3 A provision to pay cash is waived by accepting a cognovit note,4 and a provision requiring certified checks to be given is waived by accepting uncertified checks.5 A provision fixing the place of performance is waived by acquiescing in a demand for performance elsewhere.6 A waiver of interest as to one overdue instalment, is not a waiver of interest upon instalments which subsequently are not paid at maturity.7