I must commend you on your excellent memory, MTF! You're correct, the year before, we spent a week in Puerto Vallarta (around the same time).
The camera I used is a Canon SD450. Unfortunately, sand got into it on the beach and it stopped working. On Canon's behalf, I should disclose that this camera served me faithfully for over 2 years. I have since purchased the Canon SD1000 while my SD450 is being repaired.