My new site that started to rank a little bit went almost totally supplemental a week ago. I have tried to change the non www listing to a www listing with 301 redirects and the setting in the webmaster tools. It took some time but google is indexing under www but not as many pages as it is indexing in the non www. Could this be a reason to be in the sups?

I am not using any black hat techniques,i think.
I do have some backlinks but not yet counted by google.
The site is about a month old and did get a ranking for 'insert non disclosed search term here' but dissapeared into the depths of the supplementals and can not be found anymore.

It's hard to say why you went supplemental. Do you have duplicate content on your site? Or is it all original? What is the topic of your site? Do you have unique <title>s for each page?

No duplicate, and i wrote the whole thing myself.
Titles were non unique for a while but that has been fixed for some time now, little bug

It is o so strange, but i hope i get out of it.

I think you shouldn’t have to use redirect so early, redirects should be use wisely, if anything went wrong over here your site may get banned.

What is happening over here is that spider is getting same page for two url. when you apply redirect you should delete all the content of your old (moved) page, It takes nearly 2-3 months to reflect the change in index.
You can also submit re-inclusion request at google.

What is your website about?

Same here. Can somebody help me? I have 1330 pages and only 10 of them are not supplemental. It is really strange, all of the forum and auction are supplemental.

You're probably not going to like my answer, but what about emailing Google with your question? Not so much as whining but a simple inquiry where you are just looking for feedback and not for them to do anything about it for you (because that would come off as whining): "What can I do to get my site out of your supplemental index? What am I doing wrong? Is my site banned?"

Hi Dani. Thanks for the answer.. Actually i couldn't find a google contact e-mail for the specific "supplemental resuts" matter. I wrote to support@google.com it might be the wrong one )))

That is so interesting... Those GOOGLE technologies that everybody talks about are worth nothing!! All the sites with original content but extensive header and footer have lost most of their pages to suplemental sesults. I am having big problems with my auction site and GUESS WHAT, E-bay has lost 90% of its pages too.

Google's technologies are not worth nothing. They're by far the very best.

The only time people complain about it is when it is their sites not ranking well. Then all of a sudden Google is evil and incompetent. Google serves the most relevant results by far and revolutionized search.