Yahoo & Indexing – What Am I Doing Wrong?

SEO strategy and marketing techniques have certainly proved fruitful, but not quite so with other search engines, especially with Yahoo. I have been trying to index my website on Yahoo, but it doesn’t seem to allow my website to be indexed. Do you think there is something that I’m missing? I have successfully done it to Google, so I am pretty sure I have done the right steps. Is there a possibility that Yahoo isn’t accepting websites with two domains, which my site is currently having? It exists in two domains in 3dcart. While I have sought professional help, I am still not getting the answers I need. Your feedback on what I should do next will be very appreciated.