Due to a change on our domains we've had some fluctuation in the SERP's last week. I posted a message (thanks Claus for the response) right at the beginning when I was somewhat confused on what was happening. I now have more data - but have found a really weird PR issue.
The basic story:
Our web site is the name of our company - which has two words in it. We have both the hyphenated and non-hyphenated versions. Both of them used to display similar (mirrored) content. Most of the google results pointed to the hyphenated name since it had been around for a really long time. Most of the links on our site were hard coded links that referenced the non-hyphenated domain so that all visitors would eventually move over to that domain. Recently, our web host changed our domain setups and began a 301 redirect from the hyphenated domain to the non-hyphenated domain.
We had eventually talked about doing that, but hadn't expected it to happen so soon.
As a result of the 301 redirect, google is beginning to drop the hyphenated domain from the SERP's and is beginning to pick up the non-hyphenated name much more (which makes sense).
HOWEVER - this is the crazy part, if I manually type in our web address and display/refresh the page, we have a PR of 5 (which is reasonable based upon the size of our site and the incoming links). If I search for the keywords that most people use to find our site (which we fell from #3 to #17, then up to #10), and then click from the google SERP's to our page, it shows a greyed out PR.
If I click through that same keyphrase search on Yahoo to our site, it shows the PR of 5. It's only when I click through from google that shows a greyed out PR.
How in the world can a google click through effect the displayed PR value on a site?
I'm inclined to think it's some sort of fluke/quasi-penalty that is hanging around due to google watching our two "mirrored" domains - a safegaurd it had in place to avoid both our domains placing in the SERP's.
Does my inclination sound correct? And, will it "fix" itself over the next few weeks?