tedster - 9:03 pm on Jan 17, 2009 (gmt 0)

Is your PR0 a gray bar on the toolbar, or a white bar? Only a white bar is a true PR0 - the graybar means "no information." For this reason, some PR tools report it as "NAN" and not 0.

As you can see around this forum, the so called "gray bar disease" is becoming quite widespread, removing PR information from the public toolbar display for many reasons. Sometimes Google seems displeased with the way backlinks are acquired - such as links forced by wordpress "sponsored templates" or other widgets that require a backlink. Sometimes the pages that went graybar appear to be link collections with little value to users.

The most important question is whether your traffic and ranking are affected. In many cases, they are not.