We did a 301 redirect oursite.com to www.oursite.com when the was created. Google and other search engines can follow the redirect normally. But Yahoo seems to have problem in following it. It keeps displaying the non-www version in the search result with a pretty bad ranking, although occasionally the www version shows up with a much better rank. I did some searches and found a lot similar complaints about the same problem, but failed to find a solution to this. Does anybody know a solution? Thanks in advance for the input.