Moreover, on my Mac Pro, there were regular audio drop-offs (1/10 sec or so). Often (but not only) when I dragged a new track in the other deck. They were really freezes, cause both decks stopped playing... being live on air while that happens several times an hour => awful!
So here's how you go back on the Mac: Go to Applications/Native Instruments/Traktor 2/Backup. You'll find your old Traktor 2.1.2 (R12125).app". Just replace Applications/Native Instruments/Traktor 2/Traktor.app with that one and you're good to go