South of the border

A co-worker who is a member of the official Rolling Stones Fan Club forwarded to me a recent e-mail announcing a new concert date. See if you can figure out what's wrong with the first line of the message:

Dear Stones Fan,

The Rolling Stones are bringing their "A Bigger Bang" World Tour to South America, with a new concert date announced for Mexico City's Foro Sol stadium!

Um, the last time I checked, Mexico was still part of North America. Has someone gone and moved the Panama Canal to the Texas border without telling the rest of us?