Guild Wars 2

For the action bar tooltips I know it’s:

damage = weapon strength * power * skill coefficient / foe’s armor
where foe’s armor is 2600 for a level 80 character

For the Hero Panel / Weapon Skills the damage is lower:
Ex.
– action bar: Flamestrike – 160 dmg ~= 952,5 * 1000 * 0,44 / 2600
– hero panel: Flamestrike – 120 dmg ?

Some help please?
Why is the damage lower, what changes?

I have a weird passion for numbers, please help me put it at rest.