I have always been able to turn editing on and delete, suddenly, no more. I have to set news items to "0" in course and delete it. What is up with that? I don't think it began until the 2.7.4 update.
Your Moodle instance must have been broken
Setting to 0 to be able to delete has always been the case (you could delete it from the course but it would come back if you didn't set to O), see Moodle 1.9 docs for example.