Commencing with the final: I've no idea why that error appears. I just edited the photo with PhotoFiltre Studio X, a very good software.
And thank you for your words. It's not so hard for me to be pleased. If Kr had a good AF system, now I was a pentaxian. Yes, 550D is a good camera, especially for my hobby, the astrophoto/film. The Movie Crop feature is astonishing.
PS: look another picture (50mm, f/1.8@3.2). Maybe the Exif is modified by the forum. By the way, with Kr I didn't even dream to take a picture like this.
PS: I stop now my pleading, because I don't want to disturb some people with blinders.