Snap FK/IK does not copy the motion I have had an amazing problem about IK and FK mode. Snap is used to copy the animation from IK to FK or from FK to IK. So, normally, When i do an animation using IK and FK mode, I can finally run it in each mode without loss for any motion. but in http://www.pasteall.org/blend/34672 , I remark that when i run it in IK mode for all bones, the hands did not move. What is the problem?
When editing the walkcycle action alone (file has the same issue as in this question) you haven't properly keyframed the IK-arms. In the timeline set the VisualLocRot as keying-set:



Go to the keyframes in IK mode and place the hands where you want them to be. Thereafter you can switch seamlessly between IK and FK mode.