Version: 2.70 test build (win 64)
How to reproduce:
- Open a new file in blender and link the group in the provided file (or any group with an armature, really)
- Make a proxy of the armature.
- Go into pose mode, select a bone, and hit H to hide it
- Note that using ctrl+Z does not undo the hiding of the bone.
Given that the hotkey for hiding is right next to the hotkey for moving (H and G, respectively), this has the potential to seriously confound new users learning character animation in Blender. Alt+H of course works, but many users do not know Alt+H. Their initial response will be to hit ctrl+Z, like after any mistake in Blender, and this ought to work just as well.