I have a Gitzo series 3 tripod, a Neewer leveling base, and a RRS BH-55 ballhead, which has a RRS quick release clamp. The tripod, leveling base, and quick release clamp each has a spirit level. With all three bubble levels centered, if I loosen the RRS's base lock and rotate the ballhead on the center axis, within 45 degrees rotation, the RRS clamp's spirit level is no longer centered. My camera's digital level also shows that rotation from the initial point causes the camera to become unlevel. So, I don't think that one or more of the spirit levels is wacky, rather that there's something inherently wrong in how I'm setting this up.
This has left me scratching my head second guessing what I'm doing. My guess is that I am obviously missing some fundamental aspect of leveling a tripod. Where have I gone wrong? Your input is very much appreciated. Thanks!