I had binding problems with duplicating the rigged right arm layers
to create the left arm so instead I created three new layers for
the left arm. Then I marked Arm_Top_Right, choosed edit copy from the menu,
marked Arm_Top_Left and choosed paste from menu.
The same with Arm_Bottom_Right and Hand_Right.
Then I rigged the left arm with three new bones and bound three bones to the left arm.
But if I start the left arm moves to the place where in Frame 0 the right arm is without the bound bones.
In Frame 0 I have this (left arm is left):

On Frame 1 I have this:

And on frame 24 I have this:

So why are the vectors moving and why without the bound bones?
And I'm also confused about the three different pictures
I have if I click on "Selecet Bone" or "Offset Bone" an Frame 0
or the picture on Frame 1.
So what could be wrong?