What steps will reproduce the problem?
1. Have MonkeyQuest showing the list of quests.
2. Click on a quest.

What is the expected output? What do you see instead?
Expect to see the clicked-on quest selected in the quest log with its full quest text.  Instead, the quest log is opened, but the clicked-on quest is not selected and thus the quest text for the correct quest is not shown, and an error is generated.

What version of the product are you using?
v2.9.3

Do you have an error log of what happened?
Date: 2009-08-06 00:08:10
ID: 1
Error occured in: Global
Count: 1
Message: ..\AddOns\MonkeyQuest\MonkeyQuest.lua line 1286:
   attempt to compare nil with number
Debug:
   (tail call): ?
   Decursive\Decursive.lua:864
      Decursive\Decursive.lua:857
   [C]: ?
   MonkeyQuest\MonkeyQuest.lua:1286 MonkeyQuestButton_OnClick()
   [string "*:OnClick"]:1:
      [string "*:OnClick"]:1
AddOns:
  Swatter, v5.6.4380 (KangaII)
  Corpse, v3.2.0.1
  Ace2, v
  Ace3, v
  AddonLoader, v2.0
  Afterlife, v62779-R2
  Armory, v7.0.2
  ArmoryGuildBank, v7.1
  Atlas, v1.14.1
  AtlasBattlegrounds, v1.14.1
  AtlasDungeonLocs, v1.14.1
  AtlasOutdoorRaids, v1.14.1
  AtlasTransportation, v1.14.1
  AtlasLoot, vv5.07.01
  AtlasQuest, v4.3.4
  AucAdvanced, v5.6.4380 (KangaII)
  AucDb, v5.1.DEV.3583
  AucFilterBasic, v5.6.4380 (KangaII)
  AucFilterOutlier, v5.6.4380.2531
  AucMatchUndercut, v5.6.4380.2531
  AucScanData, v5.6.4380 (KangaII)
  AucStatClassic, v5.6.4380 (KangaII)
  AucStatHistogram, v5.6.4380 (KangaII)
  AucStatiLevel, v5.6.4380 (KangaII)
  AucStatPurchased, v5.6.4380 (KangaII)
  AucStatSales, v5.6.4380.2842
  AucStatSimple, v5.6.4380 (KangaII)
  AucStatStdDev, v5.6.4380 (KangaII)
  AucStatWOWEcon, v5.6.4380.2530
  AucUtilAHWindowControl, v5.6.4380.3311
  AucUtilAppraiser, v5.6.4380.2530
  AucUtilAskPrice, v5.6.4380.3175
  AucUtilAutoMagic, v5.6.4380.3142
  AucUtilCompactUI, v5.6.4380.2530
  AucUtilEasyBuyout, v5.6.4380.3583
  AucUtilFixAH, v5.6.4380 (KangaII)
  AucUtilItemSuggest, v5.6.4380.3108
  AucUtilPriceLevel, v5.6.4380.2545
  AucUtilScanButton, v5.6.4380.2530
  AucUtilScanFinish, v5.6.4380.2530
  AucUtilScanProgress, v5.6.4380.2530
  AucUtilSearchUI, v5.6.4380.3655
  AucUtilSimpleAuction, v5.6.4380.0
  AucUtilVendMarkup, v5.6.4380.2530
  AutoBar, vv3.01.02.23 beta
  Babble22, v2.2.$Revision: 1247 $
  Babylonian, v5.1.DEV.130
  BabyWigs, v0.1
  BagSlots, vv1.3.1
  BeanCounter, v5.6.4380 (KangaII)
  BigWigs, v2.0
  BigWigsTBC, v2.0
  BurningMuffin, v
  Cartographer, v2.0
  CartographerBattlegrounds, v2.0
  CartographerCleanup, v1.0
  CartographerCoordinates, v2.0
  CartographerData, v1.0
  CartographerFoglight, v2.0
  CartographerGroupColors, v2.0
  CartographerGuildPositions, v2.0
  CartographerIcons, v1.0
  CartographerIconsCtMapModPack, v1.0
  CartographerIconsDotsPack, v2.4b
  CartographerIconsGathererPack, v1.0
  CartographerIconsMetaMapPack, v1.0
  CartographerIconsSmallBoxPack, v1.2.2
  CartographerIconsSmallDiamondPack, v1.0.1
  CartographerImport, v1.0
  CartographerLookNFeel, v2.0
  CartographerMailboxes, v1.0
  CartographerMinimapCoords, v3.10a
  CartographernnTrainers, v1
  CartographerNotes, v2.0
  CartographerNoteshare, v1.0
  CartographerNoteTarget, v0.3
  CartographerPOI, v2.0
  CartographerQuestInfo, v
  CartographerQuestObjectives, v0.9b
  CartographerQuests, v0.2
  CartographerStats, v1.0
  CartographerTrainers, v1.0
  CartographerVendors, v1.0
  CartographerWaypoints, v2.0
  CartographerZoneInfo, v2.0
  Castbars, v
  ChatTimeStamps, v1.6
  ClassLoot, vr83
  CloseUp, v3.2.001
  Configator, v5.1.DEV.130
  DebugLib, v5.1.DEV.130
  Decursive, v2.4.2_beta_6-12-g708f71e
  DotDotDot, v1.13.$Revision$-W
  DrDamage, vr1063
  DurabilityStatus, v
  EasyMail, v
  EmoteList, v0.4
  Enchantrix, v5.6.4380 (KangaII)
  EnhancedCharStats, v1.3
  Examiner, v09.05.24
  FlightMap, v
  FocusFrame, v2.5.2
  FollowMe, v
  Fortress, v1.11.2-6-g4ffc286
  Gatherer, v3.1.13
  GathererDBWowhead, v1.0.2009-02-18
  GatherMate, vr671
  GatherMateCartImport, v1.0
  GatherMateSharing, v1.3
  GoingPrice, v3.1.1
  GoingPriceAllakhazam, v3.1.1249485218
  GoingPriceWowhead, v3.1.1249480192
  GryphonsRemover, v3.1
  HandyNotes, v1.1.4
  HandyNotesCityGuide, v1.0.1
  HandyNotesDirections, v1
  HandyNotesFlightMasters, v1.0.3
  HandyNotesGuild, v1.0
  HandyNotesMailboxes, v1
  HandyNotesOpenPVP, v1.3
  HandyNotesTrainers, v1.1.9
  HandyNotesVendors, v1.1.6
  HiddenReps, v0.1
  Informant, v5.6.4380 (KangaII)
  InspectEquip, v1.5.0
  LibBabbleBoss30, v
  LinkWrangler, v1.78
  LittleWigs, v3.0.0
  LittleWigsTBC, v
  LiveDamage, v003
  MaterialsTracker, v30200.01
  MillHelp, v1.2.2
  MillHelpGlyphs, v1.2.2
  MobMap, v341
  MonkeyBuddy, v
  MonkeyLibrary, v
  MonkeyQuest, v
  MonkeySpeed, v
  Nauticus, v3.2.0
  Omen, v3.0.7
  OmniCC, v2.5.6
  Outfitter, v4.7.4
  PartySpotter, vv5.16.30100
  Pawn, v1.2 beta 1
  ProfessionsBook, v3.0.3
  PvPFlagBroker, v1.0
  qComments, v3.1.1
  QuestAnnouncer, v0.5
  QuestHelper, v1.1.8
  QuestHistory, v
  QuestLogCollapse, v
  RatingBuster, v
  RecipeRadar, v1.31
  Recount, v
  RecountDeathTrack, v
  RecountThreat, v
  ScreenPlus, v
  SilverDragon, vv2.3.1-2-gf329bd8
  simpleMinimap, v30000-5
  SkillUp, v2.0
  SlideBar, v5.6.4380 (KangaII)
  SmartBuff, v3.1bDev2
  SomeAssemblyRequired, v
  Stubby, v5.6.4380 (KangaII)
  ThanksForTheHint, v0.5
  WhatsThis, v
  whoisspamming, v
  ZOMGBuffs, v$Revision: 79 $
  ZOMGBuffsBlessingsManager, v$Revision: 79 $
  ZOMGBuffsBuffTehRaid, v$Revision: 79 $
  ZOMGBuffsLog, v$Revision: 79 $
  ZOMGBuffsPortalz, v$Revision: 79 $
  ZOMGBuffsSelfBuffs, v$Revision: 79 $
  (ck=125d)

Please provide any additional information below.
First, I thought that maybe there was a compatibility problem with UberQuest, so I disabled it.  However, the error occurs with just the standard Blizzard quest log as well.