Aloha, I just got my hands on a WRT54G v.4 Router with 4.20.6 firmware on it. I have been trying all the different types of firmwares out there to see which one's i liked. I tried the HyprtWRT latest firmware and this is where I thought I ran into trouble. After I just finishing flashing it, i released that I just flashed it with the GS firmware. The router came up like normal, when I log into it, it shows Linksys WRT54G with Speedboost. So I attempted to flash it back with the linksys firmware, but it now tells me wrong code when I try. I can now flash my router with the DD-WRT firmware for GS routers and no longer with G firmware. It's up and running with no problem's with the GS MINI firmware v23.