It looks like it gets spell names from your main bar, even if the spell is on another bar. e.g. when I hearth (position 12, bar 6), I get a one hour cooldown display for the spell in position 12, bar 1. The same happens for spells/abilities on other bars. I use CT Bar mod.
I have the same problem, except with Autobar and Bongos. For some reason, if I use a mana ruby or a potion, it will show the cooldown of other spells.