I then went back in and edited the generic.kl and gpio-keys.kl files to the way they originally were. However, after rebooting I found that now neither the Recents/Menu capacitive key nor the Back key are working. When pressed, they light up but nothing else happens. To make matters worse, the Power key does work either. So when the unit turns itself off I now have to pull the battery, then I can press the Power key to boot the phone back up. However, once the phone has booted pressing the power key again does nothing - neither a short nor a long press.
I have looked over the edits to those two files carefully but don't see what I've screwed up. I even copied them to my PC and used Notepad++ to see if anything would be obvious. I have now done everything I can think of with no effect including a complete factory reset.
Can someone upload their working copies of these two files so I can compare to mine and see what I've done? If you have any other theories, I'd appreciate hearing them as well. Thanks in advance!