Well, although I'm quite sure I had wired my speakers correctly, I decided to follow the 4806 analysis and swapped the cables for the front l/r, center (according to the receiver they were out-of-phase) and back surround l/r. Then setup complained the back surround were not connected! So, I went and rechecked the cables (long-run cables), after rechecking, ran again and the receiver complained the back surround l/r were out-of-phase! So, I swapped the cables (back to their original position) and ran again. Voila! Finally I got through the speaker detection phase! Why on earth does it think my front l/r and center were out-of-phase I do not know.
So finally ran the last phase and chose 6 positions to get a better EQ. At the end it told me I had all small speakers (not true but hey who am I to argue ?), but it correctly set the time/distance and the crossover looked alright.
Reading through this thread, I read that for eletrostatic (I have 5 Marting Logans) it would be advisable to do readings at the same position at two different height levels, so I re-ran everything again and chose 8 positions (in reality 4 positions taken at 2 different height levels). And now yes got the results I wanted, Front L/R-Large, Surrond L/R-Large, the rest Small and the crossover looked alright.
I'm still puzzled as to the phase issue with the Front and Center, given the problem I had with the back surrounds, I suspect it maybe a cable issue although the Fronts have pretty good cabling (Audio Quest Granite) and the Center a Monster with a good gauge.
In the end a Happy Ending with a Mystery
The sound is really great, the Audyssey and Flat EQs sounding really fine, my son (6-year old) is already watching his movie while I got do some chores - wish I could join him