Wow, sorry to hear that. My Garmin zummo is about 6 yr old and doesn't seem to work as good as it used to. I have updated it but after trying to use it on a simple run yesterday and having it give 4 glitches telling me to exit etc, I decided to pay $55.00 to load the new maps. I ran the same route today and 2 1/2 of the glitches were gone. There has been a lot of road work in this area so I will be trying it elsewhere. I know it's a tool that is a guide and not 100% but it can really stress you out when it's throwing out bad info.
Same happens with my smart phone. It works pretty good but loses connection in some areas that are not remote by any means. It seems to have a lot of trouble around Denver. I may have to start going over google maps before I head out and write down all the turns. It's stressing me out and just far to intense. It seems to me that when I first got it, it was perfect and a real help.