normally, the firmware update program should check if drive and firmware to be flashed match.
What I'd try at the moment:
1. uninstall both optical drives from device manager then reboot. See what happens.
2. open your computer and disconnect the combo drive (which should be your 4480. What happens now?
One LG GSA H55N a combo cd writer and the other one LG GCC-4480B DVD writer.
That's not correct. The H55N is a DVD writer, the GCC-4480 is a combo drive with CD writing capabilities.