Movement problems

Hi! I have problems with Hexy’s movements. The fact is that servos are working perfectly fine when turned on separately. Even a separate leg is working perfectly fine (e.g. wave command). However, when I turn on all the servos, something weird happens and they start moving very weird. E.g., if I give a command set zero or get up, the legs just twitch and curl.

Update:
From what I’ve gathered from the Forum, it might be a problem with the power supply. Initially I used four AA rechargeable NiMH batteries. However, I also tried connecting V6 adapter and the result was the same: once I turn on more than three servos, they start moving uncontrollably.

Ok, false alarm. It appears the batteries were the problem. I guess they were not charged properly or something else went wrong, but once I connected an adapter (arcbotics.com/products/hexy/powering-hexy/), everything started to work!
So if you have similar problems, I suggest trying to operate separate servos first. If they work properly one by one (try Wave in PoMoCo), but refuse to work together (Get Up and basically any other command), than it’s highly likely that powering is the culprit.