Every time I add a new constraint it looks like the keyboard input locks on the other tabs and I can't change the name. I have to CLEAR, then assign the pose editor again so it let's me change the name and even that is not reliable sometimes. Instead of typing it just activates the keyboard shortcuts for other functions in Unity.
One workaround is to type the names in a textfile and paste them into the textbox.
Customer support service by UserEcho