I've entered my Level 13 invoker I make from ddi into Hero Labs v8.6 and the damage is out by 6 points. I've double and triple checked everything I can think of. according to the power card the damage breakdown is +7 - +5 wisdom and +2 astral fire.
relevant stats:
Lvl 13 Invoker
Wisdom 21 (+5)
Covenant of Wrath build
Implement focus - staff
Astral Fire (feat) (+2)
Staff of Ruin +4
this tallies to +11 damage but the printout shows +17 damage.
I don't know where the last +2 might have come from, but using that data I get +15 damage, which should be correct: +5 from Wisdom, +2 from Astral Fire, a +4 Enhancement Bonus from the Staff of Ruin, and a further +4 Item Bonus from the Staff of Ruin.