I moved my four IF statements to the "correct place" in my loop and everything goes fine now.

I admit, while searching for hours in the wrong direction, I've lost the overview of the program's cycle.

So let me thank all of you one more time.

I'm finishing some cleanups and port it to a PIC12F683 (it's my first SMD project...).

Finally, I'll end this thread by attaching the ultimate code.