>I'm using 2 buttons for a range of of different functions,

You can use two buttons in one A/D pin to up or down in the menu. You can do
it using a voltage divider with same resistor ( 2,5 V in the middle) an use
the buttons to short circuit the resistor so when you press the button you
have 5 or if press the other you have 0. To use it like an interrupt it must
be pooling for change in adres register (from 2,5 to 5 ; 5 to 2,5 etc) you
must also provide a resistor to protect from a short if you press both
buttons at the same time.

Javier
vgr@interacces.cl