confirmed that code in C:\FROM_VIRGILIOS_MENUS2 compiles and works with the PIC18F4431? .
this code is called LCD_from_Menu-4431VSN.asm and includes a timer1 interrupt that toggles bit B7 at ~250Hz as well as functionality to turn TOGGLE pins B6 and B5 through menus 0-2 using key2 (the 3rd button). The 4th button should turn off these pins, but instead it freezes up the menus. So in the short term, I'm just going to use 3 buttons.