Forum Moderators: Robert Charlton & goodroi
At any rate, rather than rely on a third party tool, I would suggest examining the results when you use the site: operator on Google itself. That may give you a better idea as to what is happening.
That kind of careful, page by page inspection, may teach you something. I know I often find technical issues this way.
Also, I'd suggest looking at your backlinks (even internal) on the Yahoo Site Explorer [siteexplorer.search.yahoo.com] or any other search engine that gives more thorough results than Google's link: operator does. You may notice some oddities this way -- and if Slurp runs into something difficult, then in all likelihood Googlebot will too.
One more thing to check -- if you've got a robots.txt file, make sure it is saying exactly what you want it to say.
Run Xenu LinkSleuth over your site and make sure that there are no problems with the navigation. Make sure too, that all non-www URLs are redirected to www and that the status is "301".