Backlinks Causing Penalty?

Can backlinks create a duplicate content penalty

[Jimville]

My site is www.my-web-site.com. It has over 700 backlinks on Google (PR 7).

Yahoo! is ranking my-web-site.com (no www)which has 2 backlinks.

I recently read somewhere that Yahoo! will rank pages with duplicate content, but will only consider the weaker page.

Could this be causing a lower rank than if the www.-my-web-site.com were ranked?

Thanks for your help.

[2_much]

Jimville Yahoo seems to have problems with dupe content, from 301/302 redirects to the issue you're mentioning.
First you might want to check that your server is properly configured, then maybe you could try to get those links pointing at your site with www. If neither of those works, you might want to email them to see if you have any luck.