Completely Omitted PR Bar in Google Directory

Not even PR0 - no bar whatsoever

[chrisk999]

One of my sites has the PR bar completely transparent in its listing in the Google Directory (/images/cleardot.gif).

Toolbar PR is a PR6, but the site has curiously got recently buried a long way down the SERPS, where it's held a #1 position in its keywords for some years now.

It was recently targeted by the 301 redirect problem, but I managed to get the redirecting page removed yesterday.

Could this be an intermediate phase before everything gets back to normal, or is this a sign of a penalty being applied by the big G?

Thanks in advance for any help you can offer!