Problem animating custom rig with mocap file + biped

[Anonymous]

I am trying to animate a custom rig with a mocap file, I did some research and found that I could use "retargeting" for this, but coulnd't find good info on how to do it. I also found that I could just add a biped and apply the .bip mocap file to it, then using constraints between my custom bones rig and the biped i could I could animate my rig. So i am trying to do that, it kinda works, but I have some problems with the arms, as shown on this image:

What I did is I used Orientation Constraints from my rig to the biped on all the bones, and a Position Constratin on the pelvis bone. As you can see the arms on my rig are behind the back on that frame of the animation, but in the biped the arms are in front of the body.

What could be causing this and how can I fix it?

This is the .max file im using (2014 version - 2013 version - 2012 version - 2011 version)

[paulneale]

Did you check maintain offsets in the Orientation Constraint when you added them?