I think that a proper content + some aff links is not a problem with SE.
There’s a lot of sites doing well with the above structure.
I have a site banned in Yahoo.
I have not aff links or duplicate content.
My guess is that for Y there’s something wrong in the reciprocal linking, but not sure of the exact problem.
Since I’m doing well with MSN and Google, I’m not able to change nothing.
I have indexed my homepage, then all the my links and finally all the subpages but not “cached” and without title and description.
Really odd. I was reading several SEO forums and there’s not nothing consistent about what is ongoing in Yahoo.