Reading a button Matrix on a RC Transmitter

Okay, so i have a RC Transmitter(HK-7x / KDS-7x that was fitted with an Atmega8l. With a proprietary firmware with a lot of limitations. A little probing showed promise that an arduino bootloader would really help in opening it up to everyone.
I went ahead and did just that. So right now i am able to do the analog outputs onto the RF (PPM) out. But i am failing to read the button matrix. 12buttons and 4 toggle switches in a 4x4 matrix. I am attaching the details of my investigation so far in this thread. Hope someone helps me out with that.

you can also refer to the discussion also on rcgroups - 2288086
(HK-7X / KDS-7X Radio Mod - RC Groups)

Button matrix.PNG

HK7x_modV1.ino (3.85 KB)

HK7x_modV2_control.ino (4.25 KB)

IO_board_pinout.PNG