Today, on monday 18th July 2011, after seeing all my sites (and other sites whose PR I remembered before the last update) dropping back, i tried to check the google pr for pages on all google database servers, and was bit surprised to see all of them were down! This was bit surprising to me! I am not sure if they are down due to some error, or is it because they are doing some major upgrade to their system?
Is your sites PR also down to the Previous value?