why would www.domain.com have pr but not domain.com
 

why would www.domain.com have pr but not domain.com

Because it's technically two different URLs.

hrmm
my brain hurts

because Jesus hates you

word. Just Add www at the host level if somebody goes to http://domain.com/ and all your PR will be as one.

http://www.workoutmusicvideo.com/images/yeemeditate.jpg

www. is a subdomain of domain.com. SEs treat subdomains as different "sites" and thus they each have their own PR. You need to pick either ww w.domain.com or just domain.com and make sure ALL links use what you've choosen. Also implement a permanent redirect in your .htaccess from the one you don't want, to the one you do.

:1orglaugh

Didn't know that its considered a subdomain. If you redirect in a .htaccess file. Will it hurt your pr at all? I have some domains listed as www.whatever.com/foldername/ thats a pr of 3 and the www.whaterver.com/foldername/index.html as a pr of 0 and allways wondered how to fix it. Changed all the links pointing to the page but never tried the .htaccess.

because your incoming links are to the www url

Instead of doing it with htaccess its a lot easier to just get your host to set your apache defaults (assuming apache here) so that your ServerName setting always returns the www version.
As it is a separate "subdomain" there is also a problem on some sites Ive seen where they use relative linking instead of static links, and Google (because of a bug introduced in 2004) treats these not only as two different sites, but will split subpages for the two sites which can play havoc with your SERPs (since PR really has very little to do with positioning - at least the displayed PR that is)

I'm not sure what you're asking.

That won't fix anything as it won't prevent anyone from still linking to your site as domain.com. So any SEs crawling from there will still have the 2 entries. But if you do the permanent redirect to the www., then the SE will just have the 1.

It won't hurt the PR on the www.domain.com at all if domain.com redirects to www.domain.com. I can't say whether it would affect pr on domain.com... it seems likely that it would, perhaps... but I wouldn't worry about that too much.

disclaimer: I am not a search engine guru