Hello all, I'm using pic basic pro ver 2.2 and I have a program about 500 line long. My problem is that when I place my interupt service routine eg. INCLUDE "isr.bas" at about 40 lines into the program (yes the program does jump around it) it all works fine but if I place it any where else, my program goes off into the weeds. Does anyone have any idea why the placement of an ISR in PBP is so critical or does anyone have a suggestion as to what I may have done wrong. I won't post the code unless I'm asked to due to it's length. Thankyou Regards Stuart O'Reilly