Moho Forum

because then IK rotates around the endpoint of the bone above, not the startpoint of the locked bone. Could this be looked at?

It means that while a locked bone may have its orientation locked, its position depends on how far away the tip of the parent is from its start point, and thus the bone will revolve around the parent tip, not stay stationary.

No one else noticed this?

Actually, it has been discussed many times. I recommend you this old thread
viewtopic.php?t=11457

Hmm, reading through that thread it doesn't seem to be my problem. I occasionally get the flipped bones, but that's avoidable with bone limits and keyframing usually. The problem is the IK is rotating around the tip of the parent of the locked bone, not the locked bone itself, which means the locked bone does not remain stationary if it's away from its parent. This limits the usefulness of this function.