Thing is, both background extraction and color calibration (photometric and traditional) are designed to run on linear data, but stretching removes linearity. Therefore background extraction removes more than it should and color calibration cannot calculate the correction factors properly.
This is really useful info - thanks Dimitris!
Nice work, Spooky! From a purely aesthetic standpoint, I'm a little thrown by the rotation of the image; I'm more accustomed to seeing M42 under the belt rather than to the right of it, and I might crop the shot slightly to centre M42 and the belt in the frame. But I'm new here, so you can take that with a grain of salt

Thanks for sharing!