I am a novice in the SEO/web world but I do know that toolbar PR is an unreliable factor, however, I am working on a website that was redesigned in September of 2007 and there is something I don’t understand about its PR as reported on the toolbar. Around the beginning of April 2008 the toolbar PR on all the pages in my sub-directories disappeared. In my research, I noticed the first letter of my six main sub-directories are capitalized, BUT if I go into the browser and change the capital letters to lowercase, my PR shows up again.

I looked at my Google Analytics and apparently I have traffic coming in from both versions of the sub-directory (capitalized & lowercase).

Likewise, when I search for my top keywords, the landing page that Google lists in SERPS varies from capital to lowercase and sometimes shows twice (both instances, capitalized and lowercase)

In the course of my research, I also found a blog dated May 7, 2008 that was suggesting a Google Algorithm change making Google natural searches case sensitive for keywords. Where Google used to see “Washington” and “washington” as the same keyword, now it is recognized as two separate keywords…

Google appears to Change Algorithm: Using Capital Letters Creates New Keywords | Big Oak SEO Blog

That may or may not be related, as it pertain to Google’s treatment of user queries in upper or lower case.

Here’s the real question: should I rename all my files and links to lower case?
Will if affect the page’s position in the SERPS?

I was wondering if anyone has any thoughts?... Is this an indication of Google perhaps becoming case sensitive?

I appreciate all feedback in advance.