Google has updated the PageRank bars within the Google Directory recently. The new update now matches the PageRank values of the Google Toolbar. For example, the Computers > Internet > Web Design and Development > Promotion > Weblogs category now shows my revised, penalized Toolbar PageRank score of a 4 and not a 7.
The last time Google did a PageRank Directory update was in January and at that time, the PageRank score in the directory did not match the toolbar update from November or so. For history on that, start here and go back.
A WebmasterWorld thread notes that Google has also changes the scale of the Directory PageRank bars from a 0-7 to 0-10, this way it matches the Toolbar scale. Interesting, indeed.
Forum discussion at WebmasterWorld.