Certainly shouldn't take 5 minutes to load, but sometimes a fw update will just stall for no reason at times with other Garmin units i've found. Aborting when it hangs like that, resetting the unit and trying again will often work. Strange you don't have a reset hole. Downgrading fw on most units will force a reset, but that's maybe not going to be possible as these units cannot be connected to a PC to use Updater.exe and flash an RGN file. AFAIK they can only have firmware flashed with GCD file on the card. It may be possible to fool it by renaming the older firmware as an higher version than the current one but that's untested on GW personally so i don't know how it would react. What version are you running now on it?