New patch seems to have done it to me. I never had this problem, played about 8 or 9 rounds tonight, and I suddenly have THOUSANDS of kills, tons of sniper kills (never managed to snag a sniper slot after beta), unlocked tons of achievements I didn't earn.
Worst of all, all the hard work I put into the classes and weapons I DID earn is now for poop, because it added to those, too. If everyone else is experiencing this (as I said, this hasn't effected me until tonight), we're stuck with a reset, it would seem.