Witness the importance of double checking wiring. The menu key (above the 0, is wired to the same select/return line combination as the 0 key (bottom of image). Luckily, another return line passes by and is just a matter of switching the bottom of the pushbutton to a different return line.
By simply connecting the bottom of the key to another return line, the menu key now has a unique select/return line combination.
Since these circuits are wired without using a schematic, very careful checking is needed at the end to make sure everything is wired correctly.