Tried to do the update via Firefox 13.0.1.
No flashing lights on the unit. The power light is solid blue, and the indicator lights for each of the four drives is solid green.
After about 36 hours now it still shows "Progress: The machine must be restarted to enable the firmware settings. Please wait until the restart process is complete."
Do you think it's safe to just kill the browser session, maybe restart the computer, and then try downloading the firmware from buffalotech.com to install from there? As I mentioned before, the NAS itself is still accessible via Finder, just not in NAS Navigator, which is pretty odd.