Am I the only one having serious issues with IK Contraints lately?

I can go into more detail if you want. I am trying to follow this video, http://vimeo.com/8536333. Once I get to the IK Constraints in the leg, the armature goes absolutely crazy. I will try to move the bone and it moves in the same direction at a consistent speed. Even Alt-R won’t make it return to its regular position. I must be doing something wrong. I’ve tried it in 2.58 and 2.57 and they are both showing similar crazy results. What’s the deal?

A blend file would be helpful. It might be a parenting/constraint hierarchy issue, but cannot say for sure

Here is the blend. http://www.mediafire.com/?p4pbuokx8hz3m9g

The hand IK bone and the heel bone are the main controllers for the limbs. Move them around. You’ll see how crazy they act. I have no idea how to explain this.

Yep its a parenting issue. When you use an IK controller, the controller can’t be a child of a bone on the chain, it creates an infinite loop( IK controller tries to move the forarm, but because the forearm is parent, it tries to move the IK). unparent the IK bones (or oarent the to the base or something not on the IK chain), and it will work fine.

You can attach blend files in your post when you ‘Go Advanced’.

Anyway, the hand_IK bones are parented to the forearm bones. Unparent them and it’s solved

EDIT: what daren says…

You know, I noticed that and didn’t think much of it. Thanks for the help guys, I feel like an idiot.