probably a little mistake but... From your your OPTO coupler output untill the end, ground muts be tie to GND instead of GND-A

GND-A is the PIC side ground.. right?!? Also 7805 circuit. Must be 470uF or more at the input + 0.1uF. Output 10-47uF + 0.1uF

Last thing 3.3K for the Zener diode... about 7mA... i find it's a bit low. 15-20 mA is a little bit safer. Use 1.2K