Occasionally I run into these problems. Here’s a bug, or glitch I suppose, that should get some attention.
In a nutshell, if you edit an armature in a separate layer while the mesh for that armature is in a disabled display layer, then when you enable the mesh’s layer it will not update until you edit the armature’s pose again with the mesh’s layer enabled. Video says it all.
For those who don’t know, the last thing I did was ALT+G to clear the bones pose location.