On my website (was a PR6 until the last update! now PR5) I just noticed that "index.php" has no ranking at all - a white PR0. In fact it has not even been crawled.
The reason for this - all the links back home are www.sitename.com only, not www.example.com/index.php.
So I pose the question to everyone out there who always says "it is PAGE rank not site rank" etc.... if it is page rank, what "page" is it ranking? As index.php is the entry (there is no index.htm / .html / .xhtml etc etc) but has 0 rank.
So maybe on the initial entry point, "page rank" is not such an appropriate label....
[edited by: ciml at 8:33 am (utc) on July 18, 2005] [edit reason] Examplified [/edit]
The PR is assigned to www.domain.com/, so make sure that is where all your internal and external links point to.
This is also very good advice for sites currently using index.html for the index page - make sure that you link to www.domian.com/ and if you ever change your index file to be index.php then the link will still work for all visitors, and the PR will not need to be recalculated either.