Lua Spell extra damage "0" on server log

[gldarkk]

I have one attack spell what gives condition paralyze, everything works good but my server log has one extra damage "0", dunno why
This happens on all my area spells what gives conditions (fire, poison, paralyze etc)
its like:
20:59 You deal 368 damage to a training monk.
20:59 You deal 0 damage to a training monk.
20:59 You deal 288 damage to a training monk.
20:59 You deal 0 damage to a training monk.

Spell:

Spoiler

local combat = createCombatObject()
setCombatParam(combat, COMBAT_PARAM_TYPE, COMBAT_PHYSICALDAMAGE)
setCombatParam(combat, COMBAT_PARAM_DISTANCEEFFECT, CONST_ANI_FLASHARROW)

local condition = createConditionObject()
setConditionParam(condition, CONDITION_PARAM_TICKS,1000)
setConditionFormula(condition,-0.4,0,-0.4,0)
setCombatCondition(combat, condition)

function onGetPlayerMinMaxValues(cid, level, skill, attack, factor)local min =((level /5)+ skill *5)*0.5local max =((level /5)+ skill *5)

return-min,-maxend

setCombatCallback(combat, CALLBACK_PARAM_SKILLVALUE,"onGetPlayerMinMaxValues")

local _combat = createCombatObject()

local area = createCombatArea({{1},{1},{1},{1},{3},})
setCombatArea(_combat, area)

function onTargetTile(cid, position)return doCombat(cid, combat, positionToVariant(position))end

setCombatCallback(_combat, CALLBACK_PARAM_TARGETTILE,"onTargetTile")

function onTargetCreature(cid, target)return doSendAnimatedText(getCreaturePosition(target),"Slowed!",101)end

setCombatCallback(_combat, CALLBACK_PARAM_TARGETCREATURE,"onTargetCreature")

function onCastSpell(cid,var)return doCombat(cid, _combat,var)end