A cre8asite member asks in a thread named PR on noindex pages?
Why Would goolge bother to include a PR for page that you don't want in the index... Seems odd to me...
Three different answers, all pretty valid, are brought up in response to the question.
(1) The toolbar is way out of date and inaccurate as a real time measurement.
(2) Ammon responds that this is typical of "Ghost PR" and links to two threads at Cre8asite, one from January 2003 and the other from July 2003.
(3) Then you got a detailed explanation of how the how Google indexes pages.