Steve, linking should always be done consistently. But in numerous cases that have been observed, it has nothing at all to do with how the webmaster is doing links.
The important thing is, that these are showing up where there are ONLY absolute links done one way, with the www, and ONLY links that the webmaster knows about, which are also absolute links, with the www. Even brand new domains that no one whatsoever is linking to, except maybe the web designer - with one link, absolute with the www.
They are URL only, which means that the content isn't indexed with it, and are without a shadow of a doubt coming from someplace else - from a link someplace else that is beyond the webmaster's knowledge or control.
I believe that Google is getting the URLs, wirhout the www, from a database of whois records that has access to the info as soon as a registered site is put on hosting.
I'm talking about the root domain.