I just solved this VERY same problem today! Thought about posting this same question.
I have bareshafted 6 different arrows, most of which were carbons, out of my recurve in the past couple days. I have not shot in quite a while and ALL my shafts were hitting nock left severley. I adjusted everything on the bow several times and played the weight game with the carbons.
In the end, I simply adjusted my finger pressure on the string(letting my middle finger bare most of the weight)during draw and release and BAM,Im shooting bullets, consistantly. Bareshafts shooting dead straight and all.I was torqueing or plucking the string badly.I had a feeling it was my release but couldnt seem to nail it down.
I say definetly your release.
Try that before doing anything else.