I had a problem getting grid to display a diseases icon when healing on a priest. I was doing ICC 10 heroic as part of a fun achievement run and as a holy priest, I was suppose to remove the Necrotic Plague debuff but the icon did not show up. It use to display it in the past when I was running ICC 10 back in the WoTLK.
So what has changed? I checked the options and select the diseases debuff to be displayed as an center icon but it does not show.