IK Collapse

I’ve been using http://vimeo.com/5067809 to learn rigging and IK but I’ve come to an issue with IK that I can’t find a solution for. When I pull the hand back to the elbow it just moves the hand and the IK doesn’t move until its almost in the models body. Does anyone know whats happening? I’m using my own model instead of the one in the tutorial as well.

Here’s the .blend file if that helps.

Thanks for the help.

to be honest, I haven’t even seen your blend file but from my own experience I can say that having 2 bones as an IK chain that are exactly parallel (in rest pose) wil cause problems.
try go to edit mode and move the point between the upper and lower arm just a little bit.

I consider this as a bug, because if there’s no pole target, it’s kinda logical Blender doesn’t know where to bend your chain to, however if there’s a pole target there should be (theoretically speaking) no problem.

tried on your model. works.

Wow that was way easier than I had expected. Thanks