Yup and i missed it...

What capacitor value did you put on your Crystal? 15-22pf?

what happen if you remove the MAX232, and use inverted mode for your baudrate???

With the MCLR_ON, it mean you use MCLR, so i hope this pin is tied to Vcc?

Clean psu, decoupling caps here and there?

Did you also tried with the internal OSC?

I don't see anything wrong in the code...