Endika, you were correct about the horizon tilt. To tell the truth I could not see the blotches (perhaps I had done a poor job w/ noise removal). I re-ran it thru my PP steps and paid a little closer attention to the shadows... Thanks for the help - it is appreciated :-)
This is a great scenery, and these pines in the foreground work admirably to frame and enhance the rich sky.
Pity the compression has introduced some blotches in the dark areas, this photo sure has a great richness of tones in the shadows.
BTW Isn't the horizon a bit tilted clockwise?
endika