OK I'm now a firm believer in letting any drone acclimate to the satellites for 15 minutes after calibration or if the drone is moved over 100 miles. Previously I only let it set for 12 minutes before flight. Today I used some spent batteries and let the 920 sit with power on but props off for over 15 minutes. An article that I read stated that satellite orbits are monitored by ground stations, and each satellite broadcasts the almanac every 15 minutes, IIRC. (In other words, if you can flawlessly receive one satellite for 15 minutes, you should have a complete, updated almanac.) The 920 was stable with hardly any drift horizontally and vertically. Satellites were 17 and 5 as they were 2 days ago. I am now a firm believer in letting the compass build the database of satellites before taking off. My speculation is that 2 days ago the drone had the same # of satellites but had not rec'd enough of a database to know where it was at all times and that's why the LED's cut out and the 920 didn't respond to the right joystick.