ask 863211 :strange case status update

LD\'s EB1B 140 was appoved on 06/24/2010 through PP, and we already received hard copy. Our 485\'s was approved last year based on this. However today in my email box I got case update notice from usics it said his EB1B was approved on 04/01/2011. Is something messed up there? Do we need do anything?