I am running OS X 10.6.3 on an Intel Core 2 Duo 27" iMac. I updated the Airport Utility to 5.5.1 yesterday and now all items in my iCal are duplicated (they each appear twice) and I cannot run Adobe Acrobat Pro (9.1.2). I can muddle through with the iCal problem but I work all day every day with Acrobat. Any help much appreciated.