Apart from the code you posted doesn't show the modifications you described, have you done specific tests to see that the code in the micro is working? For example: write code to output incrementing values out the data port whilst looking at the signals with an oscilloscope. You could do other specific tests like outputting certain values via the serial port to confirm that you are writing the correct values and/or you are executing certain parts of the code. You may have done something like compiling for the wrong memory model so the code will not work as you expect.