It's on FIrmware page.
Even simpler, after it falls, do you have to re-arm? If so, then it has probably reset and it is a power issue of some kind. Sometimes that is a bad battery, sometimes it is a bad connection like a bad solder joint. It could also be vibration. Does it feel like a lot of vibration if you (carefully and holding it very level) run it up to flight power in your hand?
So about FlightTime:
FlightTime counts the time since you plugged in the battery, so plug it in, wait 5 minutes, fly for 1 minute, plug it back in GCS takes another minute (none of this needs to be exact at all). It should say about 7 minutes times 60 = 420 seconds. If it says more like 60 seconds then you know it reset.
One last thing, sometimes it will reset when you plug GCS back in, so watch the LEDs to make sure that it doesn't reset then.