texasville - 5:25 am on Oct 4, 2006 (gmt 0)
I have a theory that any page on a site that doesn't have a significant backlink(s) is going supplemental. I have 3 sites I am managing now that have gone entirely supplemental except for the index page.
All of the sites have one thing in common: all links point to the .com and not to any interior pages.
One of the sites is a brand new domain as of 10 months ago and has no dupe content issues. That I am positive of. And another has had a 301 since the first week it was up and all original content.
Those two sites are merely for very small businesses and haven't had much backlink production.
The primary site has been around for a while and has run the gamut of problems but most have been straightened out for a while. The nice thing for this site is it has moved into the top ten for most of the keywords pursued for it and keeps moving up and traffic is growing for it. So, the supp issue doesn't seem to be hurting it's growth.