i think that your hardware keyboard is screwed.
but before you give it to a nokia service point i would flash the emmc and fiasco.
if its a software issue it will definetly work.
if it dont works you will know that its a hardware issue and you have to go to nokia.
and btw:
flashing will not crush your warranty.
if you dont know how to flash check the wiki out-
http://wiki.maemo.org/Updating_the_firmware