Answer:
This is purely a function of state law; the Maine answer may be different than the Minnesota answer. However, your thought process is consistent with the general concepts in "the law of agency."
An agent, authorized signer, or convenience signer has a power of attorney limited to a particular account at a particular institution. He or she has no ownership or survivorship interest in the funds. Upon the death of the person(s) who appointed the agent, the power stops.
First published on BankersOnline.com 4/01/02