(a) The death of a principal who has executed a written power of attorney, durable or otherwise, does not revoke nor terminate the agency as to the agent, or other person who, without actual knowledge of the death of the principal, acts in good faith under the power. Any action so taken, unless otherwise invalid or unenforceable, binds the successors in interest of the principal.
(b) The disability or incapacity of a principal who has previously executed a written power of attorney that is not a durable power does not revoke nor terminate the agency as to the agent, or other person who, without actual knowledge of the disability or incapacity of the principal, acts in good faith under the power. Any action so taken, unless otherwise invalid or unenforceable, binds the principal and the principal's successors in interest.