Well, I have the edge 510. Maybe because I disconnected the device from my computer (windows 7 OS), when I re-connected it, there was a pop-up window (to): Check the disk Garmin Edge 510; with the options "Automatic fix file system errors" and "Scan for and attempt recovery of bad sectors" with the first option ticked.
The first time I ignored the message. Two days later as it showed up again as I plugged my Garmin again, I hit the "start" button (still only the first option ticked).
As I tried to use the device today, the activities pages I had were missing, my profile and bike profile were missing too. I tried to change the units from statute to metric but in vain, or sometimes it changed, although in the page there was selected the other unit (ie. it showed celsius though in the units page the selected option was Fahrenheit). There were only the English language, I couldn't add an activity template or a bike. Still though, I pressed start and the activity was recorded, though only GPS data, temperature and HR. Speed was recorded through GPS, not through the speed-cadence sensor as cadence wasn't recorded. I have to notice that the sensor was identified.
Although there are rides saved in the device when you try to select them from the device it says there are no rides saved. The beep sound don't work even if you change the selection through the system menu, and although the BT sensor is not enabled the icon is flashing as it tries to connect with some device.
I tried to use webupdater to re-install the last update but to no avail.
The device's screen:
I'm also attaching 2 screenshots with the root directory of the device, plus the "Garmin" directory:
