Question : Problem: sync issue Blackberry to Outlook Tasks

1 user on our BES system started getting this issue recently: adds a Task on the Blackberry then  syncing from his blackberry to Outlook he will get an error from Outlook "cannot open item" on that new task.  
ideas?

Answer : Problem: sync issue Blackberry to Outlook Tasks

Using Desktop Manager do a Backup from Backup\Restore.  Once the backup is finished select Advanced and clear the tasks on the right hand side, once cleared select tasks on the left and restore them to the device.