Hello, load a char like in the attchement, go to designer mode, add a few bones like in the video tut "Spring animation" at Minute 7.
In the spring editor you can not select one of the bones youn have just created, when you click on one, it blinks blue then goes back to grey and doesnt stay selected. If you now group that bone it will gruop the whole head. You must explicitely click on that bone in the layer manager to perform the spring group assignement properly. (this way the selected bone turns blue, but not by clicking at it). The screenshot shows the bone under the mouse cursor right after clicking on it. Please also note that half of the char (blue box) is selected instead of that bone.

Please dont pay attention to the wildly assigned bones on that test scene, i just threw them in there, its not a bug how the look like ;-)