pics of pcb, controller, etc....?
1. the simplest explanation is a bridge somewhere, making the switch look like it's depressed when it physically isn't. being that's it's probably 1st in the row/column, i'd start there. also check the controller, pins are spaced close there and easy to accidentally bridge.
2. pins used on microcontroller, i remember someone else having issues when one of their rows/comums was connected to one of the "INT" pins, can't remember if it was D2 or D3
3. make sure your wiring is correct in kbfirmware.com, and everything is configured correctly in the pins tab
- post pics of pcb & controller, how you have it wired, etc.