EPO? At least Garmin (or someone) has a good sense of humor.
I've been having navigation issues on my device. I see "Not Getting GPS Signal - Edge 530" post aweatherall suggested looking at the "About" screen (Menu->System->Copyright Info->About). I did and see that my GPS version is current, however, I see "EPO: Expired." So per this article (though for another Garmin device, but I assume it applies to any Garmin device), I sync'ed my device to Garmin Express. Now the "About" screen shows "EPO: Missing?" aweatherall said in the mentioned 530 post to download a *.GCD file an put it in the Garmin/RemotwSW folder. But I already HAVE this file? I went ahead and download the file anyway and put it in the desired folder. When I disconnected the Edge, it said "Updating GPS firmware." Now the "About" page says "EPO: Current" I'll go for a ride later today or tomorrow to see if this fixes some of my nav issues.
So to folks having GPS navigation issues, maybe this is ONE issue you can check and fix?