As I know Aruba doesn't use postal codes: http://www.answers.com/Q/What_is_Aruba%27s_postal_code
If I'm sending a shipping address (country: Aruba!) without postcode via PayPal API I get back an error back: "The specified country requires a postal code".
Is the postcode/zipcode required by mistake by PayPal? Or has Aruba started using postcode/zipcode?