eg. check out

http://altavista.com PR7

vrs

http://www.altavista.com PR9

both you backwards links and pagerank are affected by whether the "www" is being used

Interesting.... I just tried that on one of my sites. PR2 without the www! Eeek!

Wow , looks interesting , but my site has the same PR with or without www . Maybe it's some Google's bug

what is the reason?

This isn't a bug. It's something Google has implemented by design, because there are sites that exist where the non-www and www versions are different.

Here's an explanation of the canonical issue that you see and why the behaviour is the way that it is.

This is because Google treats the URLs as 2. Not a single page. This can also raise the issue of duplicate content for your website. I think you should select the URL with www and make the other 301 redirect to it.

If you cannot apply 301 due to any reason you should use Google Webmaster Tools (Sitemaps) to define your favourite domain. e.g with www or without www.

And just to clarify, PR or PageRank is applied to pages, not sites, so all URLs get their own PR. www is a subdomain, just like ftp ( I upload changes to ftp.forrestcroce.com ), and any number of other subdomains you could add to your site if you'd like.

In most cases it doesn't matter whether you use www or not to get to a site, and this is a meaningless hold-over from the stone age. But not always, as Adam pointed out for us. 301 redirects are a really good idea here. Ideally, most of your links will be organic ( ie created by other people without you having asked ), so some people will use www and some won't; using 301s will consolidate the links from both in Google's eyes.

2 SEO service providers wondering about this basic issue. And one of them look as it is a BUG.

Now come on chaps,

It is a 4 year old thread brought back to the light purely for the signature links.

I saw adam and forrest's posts were made today and thought another "hot" discussion. Roshan is Indian name. Feel guilty.

I'm only guilty because I wanted to make sure whoever stumbled upon this thread didn't get misinformation as the result of people claiming it's a bug (that, and anything to do with SearcH EngineS WeB or however he spells it these days usually is deeply flawed and needs to be corrected.)

Oops ... didn't look at the dates. You're right. Sorry. People have been resurrecting a lot of old threads lately, this one got me.

People have been resurrecting a lot of old threads lately

Just one "people" mainly