Hola Gentle Forumsers,
I've started this thread here since parts of the discussion may not be completely on-topic to CR.
I found I needed to renew my US Passport before I returned to CR this time round since CR requires a minimum of 6 months of remaining validity on one's US Passport for CR Immigration to allow you into the country, and I do not believe that having current valid residency status overrides this requirement.
So... I sent my old passport off (as required) with my renewal application and with the required fee plus the 'hurry-up surcharge' becasue I was expecting to le