I must say that I am quite surprised that there seems to be so little reaction to this issue. I have now managed to find very many sites exhibiting this behaviour. What is even more curious is that I have also found that some sites 'appear' to be fine until you try to navigate to the total page count and it is then that Google only shows non-supplemental pages as visible.
To take matters further and just to prove to myself that this is not another site: issue then I have found that if I search for say, www dot domainname dot co dot uk then once again the only 'findable pages are non-supplemental, once again reinforcing my view that there are very many websites in the google co uk results set that simply do not have their supplemental pages included. So, on the search 'the web' side of things I have websites with 20,000 pages indexed including say 200 non supplemental leading to only 200 being findable on the searc 'pages from the UK' side of things.
I now know the true reason for my major traffic slump.
Paul
