This happened to me in a trip through India and Singapore in July. To make things even worse, my middle initial was tacked onto my last (family) name, which was where my first (given) name should have been. If my name were John G. Smith, the tickets had it as Gsmith John. (A travel agent messed things up, not me, but that doesn't matter.)

There were only two problems:

1. Check-in agents couldn't find my reservations by family name. When I gave them the record locator or suggested they enter my given name as the family name, they found them with no trouble.

2. Miles didn't post automatically, because the name on the ticket didn't match the name on the account. I had to follow up later to get FF credit.

Other than that, no problems. No hassles with security (ten checks in four countries), lounge access, or anything else.