My camera does not hunt. Never had. After all the test I have done and the answers received, I have come to the conclusion that the AF technology in DSLRs is not always consistent and have an error, and much more with little DOF and with low light.
I read your post and I think I didn't told here but time ago I made a hard reset to my machine, but I had the same results.
I'm sorry about your problem, but I like your attitude, you see the bright side of things and now you have improved the manual focus. I would like it a lot to do manual focus, but every time i tried I had severely out of focus images. I use glasses to see and with them I see the things very little through the viewfinder, and if I put them off I don't see sharp even if I adjust the dioptric wheel. I'm glad you can.