Just arrived in Belize with my iPhone 5
Before I left Canada, I called Koodo and activated the International Combo Add-On for $40 good for 30 days.
When I turned on my phone in Belize, I was immediately connected to the local carrier BTL (good!) and received text from Koodo confirming the International Combo Add-On (good again!).
However, I have no Cellular Data. In Settings, the Cellular button is Off yet greyed out so I am unable to turn on.