On a few distributions (not to name names, but RedHat and Debian), nano comes with an annoying configuration, where backspace is a forward delete.

To fix this, uncomment the following line in /etc/nanorc:

#set rebinddelete

The GNU screen software has a similar issue. When I hit "delete" it barks "Wuff! Wuff!". You can make your screen delete work again by calling TERM=screen screen. Add alias screen='TERM=screen screen' to your bash profile to simplify your life.