One way to test your tripod/ball head combo: Simply setup up your Camera/Lens/Tripod/ballhead combo with IS turned off and focus on a target with liveview+10x and just watch it---is it vibrating/moving. If you just notice heatwave like movement, it's probably not the tripod combo. If you notice significant vibration and there are no other contributing factors such as wind, then it probably is the tripod combo. This little test answered alot of questions for me, perhaps it can help you as well.

Good luck