Commiserations indeed, Krusty. I actually came here today as by bizarre annoying coincidence I have the same (or a very similar) problem as you do. My gimbal is no longer working properly.
I had one flight this morning without incident and then when about to make a second flight I noticed that the gimbal did its usual head-shake on start-up but ended up pointing pretty much downwards. It then seemed to retry this sequence 3 more times and then gave up. The app shows the camera as red and when you go to 'fly' it says to make sure nothing is blocking the camera and then to restart the drone. I have done this about 5 times but nothing helps. And the gimbal calibration button in the app seems to do nothing (apart from giving me a spinny propeller graphic)
The camera itself is working fine - it records video, takes photos and still zooms.
I tried to call Parrot support for advice (first time I have ever called) but gave up after an hour of listening to very repetitive music and being told my call is important. Grrrr. Hate that kind of crappy telephone support system.