So I have experienced this very minor problem which is more of an annoyance than anything. While in the stock messaging app, I will send off a text and after hitting send I put the phone down and go about my business leaving the messaging app opened/displayed. The screen will eventually time out and lock which is fine but when I press the power button to wake the phone, the keyboard is still displaying although the device is locked. No biggie, I just press the back key then swipe to unlock BUT this is interfering with my music app (Power Amp) which displays the player controls while the screen is locked, so the keyboard will display instead of the player...annoying!
Simple fix would be to properly close the messaging app after I am done texting but its a habit leaving it open. Is there a feature that utilizes the keyboard while the device is locked? If so, can this be turned off? Or, is this just a bug?