My wife has a similar issue. She naturalized to American Citizenship and changed her name legally, but when we purchased the ticket in advance we have no idea US Customs would naturalize her so quickly.

It was a mess. We even bought with us a legal notice from US Customs that my wife's name was legally changed for X --> Y. But the counter agent doesn't know what to do, and then he called his supervisor, who's already mad that the lines are going so slow and yelling at his counter agents, too her documents and passport and boarding pass to the back room (always wondering what's back there), waited 15-20 minutes for him to finally come out and say "don't really know what to do, we'll let you on."

Anyway, airlines seems to freak when the names don't match.