Thank you for your response. Everyone who takes the time to work on these addons does a great job in adding to our gaming fun!
I've fixed my problem by replacing my fetish group window with Himays Group Window C2C.
This isn't a shading bug with SOE, the shading works exactly as it's supposed to so I'm not even going to get them involved . CotH is a zone-wide spell and fetish 10.9 seems to have it as a beneficial spell for group member that has a certain range. Like I said in my original post, it works fine if the group member is standing close to me, but if they are across the zone I can't cast the spell and the icon is dull. (I would get the same results if I were a priest casting a single heal on a group member across the zone.)
At this point, since I don't write interface add-ons, thus don't have the knowledge where the problem lies (with EQ2 Interface or SOE, etc), I'm going to use Himays group window and go back to enjoying the game!