"Cure Potency varies with current attack power."

If you look at your strength stat, and then down at attack power stat, you'll note they're the same. The only time this will change is when you have something that buffs your attack power, hence the "current" condition (fairly certain that means most buffs to damage, but not buffs that lower resistances like Disembowel).
I assume that you are looking at this as a DRG because DRG scales off of STR, but as a BRD when I look at attack power it scales off of DEX, at least last time i checked.