Reason why?

I noticed a difference between the DP keyword tracker tool and actual MSN search result some time back.

The DP tool was reporting my site to be listed in the 80+ range for MSN on a fairly popular term. When I looked at the actual MSN serp results I noticed my site was number 3!! yippeee...party time.

I was wondering why the difference, thinking I had finally found a fault in Shawn's great tool. However I just noticed a probable reason for it. The actual serp results are returning mysite at number 3 without the "www." where as DP is looking for my site WITH "www." included before the domain. So I browse the MSN serps to the 9th or so page and find a subpage of my site ranked for that term, and sure enough at closer inspection it had the "www." prepended. So that answers that question, and no bug found in Shawn's tool

Anyhow, that leads me to my next question? Why does MSN have my main page listed without the "www." in the number 3 spot? Not that I care too much, number 3 is number 3 with or without the "www." prepended (as my site resolves without the "www."). However it still would be nice to know.

I have a feeling that it may be to do with the FIRST link to my site from some other site (btw the link was a non requested link, all natural) was placed WITHOUT the "www.". That is probably the reason. Further opinions welcome though?

My preference though would be to have the "www." before my domain name. Hope MSN over time changes to list it as such.