From what I have seen, newer posts will have a pr of 0 for a while.. maybe the sandbox type feature or until google updates pr again.
Also, my main site might be a 5 on girlgeekette.net but many of the internal pages have pr's of anywhere from 0-5 with many in between 0 and 5.. the ones that have one being 3 4 and 5... so I am not sure that the inside ones get the same rank as the main one.
I don't really know how, but when I started the site, about 3 weeks later it had a pr of 5 whereas the sister site it came from (Which had previously had a pr of 4 when I used PHPNuke) kept its pr of 4 after having ben up for 5 years. They both use the same SEO and theme.. so I am not sure why one came new with a PR of 5..
The other thing I have had to keep in mind is PR is fine for google.. but from what my stats using awstats say (with about 2000-3000 uniquie ip address a month) it shows that Google is only about 1/3 of the search engine querys... meaing 2/3 came from other search engines.
So.. PR is fine for gogle, but for me, ti was only a 1/3 of the search engine traffic.. so time spent preparing SEO for ALL search engines is more important than just PR for google.
And, the biggest 2 SEO things I have seen take precedent are 1) CONTENT first and formost and 2) Page title seems to be right up there. Since you can put keywords in your title that you will be using in your article, the relevence factor is there..
I did not use permalinks on the old sister site - aleeya.net but i am using them now.. but the PR has not changed from a 4 from the main one.. and I started out using perma links on the new girlgeekeette.net one but I cannot say the perma links made the only difference for me
just my 2 cents..