Copy/Paste the opposite

Hey BA,

Yesterday I experience a problem with blender riging.

You can download the .blend here

I have set up an armature with IK. The problem is when i copy/paste the opposite, that juste didn’t work… I had a closer look to the name of the bones (.R .L ) and everything seems ok…
I really want to understand what is going wrong.

Also, as you can see in the blend, the IK guides (knee, elbow) moves in a crazy way. I cannot control them. I don’t understand at all why. Maybe I made a mistake with my rig ?