Someone over in the Sprint Community forum suggested installing an App called 'Spare Parts', since it allows some custom settings for the 'END' button.
I installed the app, set the END button function for 'sleep'. Now the phone END button 'locks' the screen.
And... from the Sprint Forum again... suggestion to go ahead and now remove Spare Parts and the END button function will 'stay' correct.
Yep. Did for me.
Now what this actually did I don't know, but obviously it rewrote an OS setting that got broken by something else.
Sheez!
