Can't get rid of blank iCal Alarm window

Several days ago my MacBook pro running 10.5.8 mysteriously reset its calendar to 2000. When I reset it in Preferences/Date and Time everything was fine with the exception of an ICal blank message pane/window that keeps appearing after every sleep and start-up--the beach ball twirls for about five minutes during which everything freezes or runs super slow. I found some online conversation dating to 2009 about ways to fix this, but none of them worked for me. I tried trashing the iCal App which did not work nor did running a FixToDo dmg script someone suggested. I never use iCal and would have no problem deleting the whole program if I could. All help gratefully received. Thanks v much.