The Garmin firmware updates have gradually been whittling down the more major problems with the 820. One issue I have is since 3.1, Garmin Express seems to think the unit is still on version 3.1, yet won't actually update the unit. (I have upgraded the unit to 5.1 via Webupdater...the only way that it will take a firmware upgrade). Even though the unit is on 5.1, GE will go through the motions of upgrading it to 5.1 every time I plug it in.
The 820 also won't do a wireless (Bluetooth) upgrade of the the firmware either when there are updates. (It states that it is up to date, even if it isn't)
Since 3.1, it also will not connect to Wifi. It would connect to Wifi with the original shipped firmware, but has been broken since then.
I've upgraded GE to the latest version. Completely deleted and added back the 820 to GE...multiple times.
A firmware version ago, I also tried a hard reset on the unit...no improvement.
I notice that every time I go to the 'Tools and Content" section of GE, it makes me login with my account. The data screen in this section shows that the unit is on 3.1. (again, it's been upgraded to 5.1)
My guess is that there is some file on the 820 that GE looks at that makes it think that it is still on 3.1, among other bugs.
Any thoughts or ideas?