It’s a pain with O.S. 4.3 but this is what you need to do. Delete your email on the BIS site. Hook up your BB to the DM open the “Back up and Restore” then go to advanced, then go to the box on the right hand side “device database” Clear the calendar entries. Disconnect the BB from the DM remove the battery with the BB powered on; leave it off for a minute or two. Put the battery back in, re-enter the email account(s) into the above BIS website, if your have more then one email account go into options and choose which one you want to be your default. Re-sync your BB.