Take a look at the 3 middle fingers of the left hand. As you can see, one of them behaves differently from the other two in the setup.
Why is this happening?
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All your pole targets are setup incorrectly (the pole angle). Causing the chains to move in Pose Position.
Also there is pole target on the thumb which you probably don't want.
I suggest this reading for pole targets: How to Set/Calculate pole angle of IK constraint so the chain does not move?
You don't want the fingers to have any IK. You should control them only by FK. IK fingers are very advanced and rarely needed. You can still have 1 control bone to drive the finger bone chain (scale to curl/close the finger (try it, you can't rotate the finger parts individually), rotation to point it)
Further I suggest look into some already made armatures(cgcookie flexrig, sintel, search blendswap, rigify, etc.) how it should be setup. You will have problems animating this and the animations won't look nice. There are problems with shoulders, legs and spine.