I finally fixed this issue on my priest. I had to disable Smart Debuff Manager (which doesn't play well with Pitbull anyway) and the issue poofed. I was so confused because it only happened on that one character ... of course all my other 'older' characters had already disabled the debuff portion of that addon. The priest just happened to be new enough that I hadn't set her up completely I guess.
So if you have any other addons that have to do with debuffing or that have a range check - see what happens when you disable them.