I don't know how to report/reproduce this particular bug, but the Mayor's cat, Maxine, disappeared from my current playthrough. I just got petpal and talked with Unsinkable Sam. But when I go to the Mayor's office, she's no where to be found. When I walk around the mayor's office, I hear a cat meow, but no cat. I also pressed the ~ (tilde key) to see the available NPCs, but also no cat.
If there is a place to submit my save game, I'd gladly do so.
