(a) The death, disability or incompetence of a principal who has executed a power of attorney in writing does not revoke or terminate the agency as to the attorney-in-fact, agent, or other person who, without actual knowledge of the death, disability, or incompetence of the principal, acts in good faith under the power of attorney or agency. Action so taken, unless otherwise invalid or unenforceable, binds the principal and the heirs, devisees, and personal representatives of the principal.
(b) An affidavit executed by the attorney-in-fact or agent stating that the attorney-in-fact or agent did not have, at the time of doing an act under the power of attorney, actual knowledge of the revocation or termination of the power of attorney by death, disability or incompetence, is, in the absence of fraud, conclusive proof of the nonrevocation or nontermination of the power at that time. If the exercise of the power requires execution and delivery of an instrument that is recordable, the affidavit when authenticated for record is likewise recordable.
(c) A special power of attorney created before September 4, 1988 shall be construed to grant the attorney-in-fact the powers set out in that special power of attorney.