I know what it looks like. :/
I just just this and it works fine while on my actionbar. I added 5 to my inventory (Max stackable amount), put it on my actionbar and clicked it 3 times. No highlight visual issue.
I used http://www.wowhead.com/spell=33208 to trigger the item and here is the rest of my row data:
- class: 0
So, I don't know how it is doing this to you.