Confirmed. PR update on some but not all of my domains.
Mind you it means zilch. One of my competitors rank on #2-3 since last 2 weeks while they were ranking #7-10 before for 74k extact term search.
They were PR4 and they are PR3 now after the update.
The moral of PR update is simple; unless you are selling links, or looking to sell a site, PR updates mean nothing when to comes to ranking > traffic > conversion.