Canucker,
You are mistaken, as of the last few months or so, most
banks in PV are asking for a passport to cash travelers checks as it is easier for them to document larger amounts of money brought in via travelers checks. (They are starting to track checks cashed by passport number to crack down on people illegally bringing in unclaimed amounts of money.)
In the future, I have heard all banks and cambios here will require a passport for all travelers checks to be cashed. And.....it will not be long that most countries will require a passport for entry.
Remember, I live here so I am pretty up to date with what is happening. What you experienced last trip, to even yesterday can change on the drop of a dime....kinda like the
weather.