Backlinks, Allinurl, etc.

Why the large differences?

[danag]

I'm sure this has been asked here before, but I can't find a definitive answer. The following results are obtained for our site:

link:http://oursite.com 125
allinurl:oursite.com 1250
+"oursite.com" 2800
@"oursite.com" 2800

How are these huge differences explained. Nealy all of the links in all of the above are from other sites and not from our own pages.

Much thanks for your help.