Forum Moderators: Robert Charlton & goodroi
I'm happy to ask some of my colleagues to check into the issues that have been raised here.
In the meantime, though, I'd like to assure you that any negative shifts you see in TB PR are not likely to signal either very-recent or impending problems with your site. We update the TB PR semi-regularly, but not on a basis in which you'd want to use it for real-time forecasting and analysis ;)
In other words, this isn't the way we communicate that your site is violating our guidelines (unlike our Webmaster Tools, where Webmasters of penalized sites can often find a warning/status message).
I would chalk this all up to a glitch, probably related to an upcoming PageRank update.
The little green bar can really be a distraction for some and unfortunately drive bad decisions on how to make that little bugger go north...
Frankly, I haven't used it as any type of measuring stick/business decision tool for the last 3 years...and I have never had any problems with Google because my decisions are all about site usability, human user satisfaction...and conversions...
However, real PR is updated continually behind the scenes these days -- that is, the actual PR value that Google uses for ranking their search results. A PR update only means that a "snapshot" of PR is taken and exported to the toolbar servers. Last January, Matt Cutts called it "pretty much a non-event" at Google.