I have a rooted Nook Touch. It lacks BACK button, so I remapped LEFT_PAGE_FORWARD button to BACK. Changed files /system/usr/keylayout/TWL4030_Keypad.kl and /system/usr/keylayout/omap_twl4030keypad.kl for this. This button now works as BACK in new android apps that came with and are allowed by rooting. But not in some original B&N apps, most importantly not in B&N reader. I downloaded another reader app, CoolReader. And BACK button in it brings me to some file listing screens, not to the really previous screen. Why BACK doesn't work in some apps (and works wrong in some others)? How can I make it systemwide and correct?