backlinks: what differnce between http://www and www.

the two backlinks checks are different

[gordseo]

I couldn't find any posts on this. When I do a backlink check like this:

link:http://www.mysite.com
and
link:www://mysite.com

the two produce different results. One site in particular is missing and is a valuable site to have a link from. Does anyone have insight into the differnce?

Thanks