Adafruit tfp401 Hdmi/DVI converter doesn't scale screen(800x480)

Hello , 
 
I have a Adafruit TFP401 HDMI/DVI converter module. On my orange pi pc plus with Armbian kernel 3.4.113, i changed resolution to 800x480 on script.bin file and screen doesn't fit, it has margin from left. anyone help me ?

Module

https://learn.adafruit.com/adafruit-tfp401-hdmi-slash-dvi-decoder-to-40-pin-ttl-display/overview

Screenshot

http://hizliresim.com/yEAaoy