After selecting and moving some controllers in PRV track 15, I end up with a stray controller at position 74:01:000 that I can't delete.
 
There should be no controllers in Channel 9.
 
What's more, it doesn't show in the Event List view either.
 
After saving, closing and reopening Sonar it's still there. 
  
See arrow below: 
 


 
This shot shows where the controller should be according to the PRV:
 
 
 
How do I delete this controller?
 
 
Steve