I've been experiencing this issue with Garry Pye's Toodees characters. When changing the Bone Hands, a Time Warp is created which throws the right arm haywire. I just realized how funny this all is when appreciating the cavemen Toodees. Anyway, I'm able to delete the Time Warps which solves the issue until I animate further (changing the Bone Hands) and another Time Warp going further in time.