What steps will reproduce the problem?
1. Seemingly random error when I turned in a quest.
2.
3.

What is the expected output? What do you see instead?

What version of the product are you using?
0.66

Do you have an error log of what happened?
msg: Interface\AddOns\QuestHelper\routing.lua:418 attempt to perform arithmetic on local 'index' (a nil value)
toc: 0.66
v: 0.66
game: 3.0.3
locale: enUS
timestamp: 2008-11-15 02:04:17

(Routing error)

addons:
  Atlas, v1.12.3
  AtlasBattlegrounds, v1.12.3
  AtlasDungeonLocs, v1.12.3
  AtlasFlightPaths, v1.12.3
  AtlasOutdoorRaids, v1.12.3
  AtlasLoot, vAtlasLoot Enhanced v5.02.00
  AtlasLootWrathoftheLichKing, v5.02.00
  AtlasLootFu, v1.2
  AucAdvanced, v5.1.3824
  AucFilterBasic, v5.1.3824 (SnaggleTooth)
  AucScanData, v1.2
  AucStatClassic, v5.1.3824 (SnaggleTooth)
  AucStatHistogram, v5.1.3824 (SnaggleTooth)
  AucStatiLevel, v5.1.3824 (SnaggleTooth)
  AucStatPurchased, v5.1.3824 (SnaggleTooth)
  AucStatSimple, v5.1.3824 (SnaggleTooth)
  AucStatStdDev, v5.1.3824 (SnaggleTooth)
  BeanCounter, v5.1.3824 (SnaggleTooth)
  BonusScanner, v4.2
  Cartographer, vr2273
  CartographerBattlegrounds, v2.0
  CartographerCoordinates, v2.0
  CartographerFoglight, v2.0
  CartographerGroupColors, v2.0
  CartographerGuildPositions, v2.0
  CartographerInstanceLoot, v2.0
  CartographerInstanceMaps, v2.0
  CartographerInstanceNotes, v2.0
  CartographerLookNFeel, v2.0
  CartographerNotes, v2.0
  CartographerPOI, v2.0
  CartographerProfessions, v2.0
  CartographerWaypoints, v2.0
  CartographerZoneInfo, v2.0
  DetachedMiniButtons, v0.9.47
  Dominos, v1.8.0
  DominosBuff
  DominosRoll
  ElkBuffBars, v2.2.2-140
  Enchantrix, v5.1.3824
  EnchantrixBarker, v5.1.3824 (SnaggleTooth)
  EnhTooltip, v5.1.3715
  Gatherer, v3.1.7
  GuildLaunchProfiler, v00.08.00BETA
  Informant, v5.1.3824
  Livestock, v1.0.7a
  MikScrollingBattleText, v5.3.26
  nQuestLog, v1.0 r194
  Omen, v3.0.2
  Outfitter, v4.3b11
  Prat30, vRC4
  Prat30HighCPUUsageModules
  Prat30Libraries
  QuestHelper, v0.66
  RatingBuster, v1.4.0 (r177)
  Recount, v939
  simpleMinimap, v30000-3
  Skinner, vb1.9183.3
  SlideBar, v5.1.3824 (SnaggleTooth)
  SmartyCat, v1.0
  Stubby, v130
  Swatter, v5.1.3824
  TitanAmmo, v4.1.1.30000
  TitanBag, v4.1.1.30000
  TitanClock, v4.1.1.30000
  TitanCoords, v4.1.1.30000
  TitanGoldTracker, v4.1.1.30000
  TitanItemBonuses, v4.1.1.30000
  TitanLootType, v4.1.1.30000
  TitanPerformance, v4.1.1.30000
  TitanRegen, v4.1.1.30000
  TitanRepair, v4.1.1.30000
  TitanVolume, v4.1.1.30000
  TitanXP, v4.1.1.30000
  Titan, v4.1.1.30000
  XPerl, v3.0.1f
  XPerlArcaneBar
  XPerlCustomHighlight
  XPerlPartyPet
  XPerlParty
  XPerlPlayerBuffs
  XPerlPlayerPet
  XPerlPlayer
  XPerlRaidAdmin
  XPerlRaidHelper
  XPerlRaidMonitor
  XPerlRaidPets
  XPerlRaidFrames
  XPerlTargetTarget
  XPerlTarget
  DBMCore
  DBMPartyWotLK

Please provide any additional information below.