while targeting a party member buff i got this

Date: 2009-04-15 17:56:44
ID: 4
Error occured in: Global
Count: 43
Message: ..\AddOns\XPerl\XPerl.lua line 1939:
   attempt to call global 'UnitFullName' (a nil value)
Debug:
   (tail call): ?
   [C]: UnitFullName()
   XPerl\XPerl.lua:1939
      XPerl\XPerl.lua:1936
   XPerl\XPerl.lua:1957 XPerl_TooltipSetUnitBuff()
   XPerl\XPerl.lua:3283
      XPerl\XPerl.lua:3276
AddOns:
  Swatter, v5.4.4157 (WallabyII)
  Ace3, v
  AckisRecipeList, v1.0 RC6 1662
  AdvancedTradeSkillWindow, v
  Altoholic, v3.0.008b
  Atlas, v1.13.0
  AtlasBattlegrounds, v1.13.0
  AtlasDungeonLocs, v1.13.0
  AtlasOutdoorRaids, v1.13.0
  AtlasTransportation, v1.13.0
  AtlasLoot, vv5.04.00
  AtlasLootFu, vv5.03.02
  AtlasQuest, v4.3.1
  AucAdvanced, v5.4.4157 (WallabyII)
  AucFilterBasic, v5.4.4157 (WallabyII)
  AucFilterOutlier, v5.4.4157.2531
  AucMatchUndercut, v5.4.4157.2531
  AucStatClassic, v5.4.4157 (WallabyII)
  AucStatHistogram, v5.4.4157 (WallabyII)
  AucStatiLevel, v5.4.4157 (WallabyII)
  AucStatPurchased, v5.4.4157 (WallabyII)
  AucStatSales, v5.4.4157.2842
  AucStatSimple, v5.4.4157 (WallabyII)
  AucStatStdDev, v5.4.4157 (WallabyII)
  AucStatWOWEcon, v5.4.4157.2530
  AucUtilAHWindowControl, v5.4.4157.3311
  AucUtilAppraiser, v5.4.4157.2530
  AucUtilAskPrice, v5.4.4157.3175
  AucUtilAutoMagic, v5.4.4157.3142
  AucUtilCompactUI, v5.4.4157.2530
  AucUtilEasyBuyout, v5.4.4157.3583
  AucUtilItemSuggest, v5.4.4157.3108
  AucUtilPriceLevel, v5.4.4157.2545
  AucUtilScanButton, v5.4.4157.2530
  AucUtilScanFinish, v5.4.4157.2530
  AucUtilScanProgress, v5.4.4157.2530
  AucUtilSearchUI, v5.4.4157.3655
  AucUtilSimpleAuction, v5.4.4157.0
  AucUtilVendMarkup, v5.4.4157.2530
  Babylonian, v5.1.DEV.130
  Bartender4, v4.3.1
  BaudBag, v1.4
  BigBrother, v
  BossTactics, v2.5
  BrokerFactions, v1.9b
  Cartographer, v2.0
  CartographerBattlegrounds, 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
  CartographerWaypoints, v2.0
  cAutoConfirm, v1.3
  CharacterProfiler, v3.0.1
  ChatMOD, v131
  Configator, v5.1.DEV.130
  DBMBurningCrusade, v
  DBMCore, v
  DBMLDB, v
  DebugLib, v5.1.DEV.130
  ElkBuffBars, v2.2.3-148
  EnhTooltip, v5.1.3715 (SnaggleTooth)
  EquipCompare, v2.16
  EventAlert, v4.0.6
  EveryQuest, v$Revision: 48 $
  Factionizer, v30008.4
  ForgottenChat, v4.1
  GemHelper, v1.8.1
  GFWFactionFriend, v3.0.2
  GoGoMount, v0003010100
  Historian, v1.2.8
  idQuestAutomation, v
  Informant, v5.4.4157 (WallabyII)
  ItemRack, v
  LightHeaded, v278
  ManyItemTooltips, v
  myReloadUI, v1.7
  Overachiever, v0.40
  OverachieverTrade, v0.40
  Panda, v3.0.9.20
  PassLoot, v3.4
  Postal, v3.1.0
  QBar, v09.03.08
  QuestHelper, v0.100
  QuestMods, v
  RatingBuster, v
  ReagentRestocker, v0.9c
  ReagentRestockerlibsAceLibraryAceLibrary, v
  RecipeRadar, v1.31
  Sea, v
  SendSelf, vv2.5.0
  SharedMedia, v3.0
  SilverDragon, vv2.2.2-1-g960ba3e
  simpleMinimap, v30000-3
  SlideBar, v5.4.4157 (WallabyII)
  Stubby, v5.4.4157 (WallabyII)
  Talented, v2.0
  Titan, v4.1.9.30100 - Revision 216
  TitanAmmo, v4.1.9.30100
  TitanBag, v4.1.9.30100
  TitanClock, v4.1.9.30100
  TitanCoords, v4.1.9.30100
  TitanFriends, v3.0.0
  TitanGoldTracker, v4.1.9.30100
  TitanLogout, v1.2
  TitanLootType, v4.1.9.30100
  TitanPerformance, v4.1.9.30100
  TitanReagentTracker, v1.3.1
  TitanRepair, v4.1.9.30100
  TitanSkills, v1.0.8
  TitanVolume, v4.1.9.30100
  TooltipOnMouse, v1.04
  TrainerSkills, v3.11c
  WintergraspTimer, vbeta16
  XLoot, v0.9
  XLootGroup, v0.5
  XLootMaster, v0.7
  XLootMonitor, v0.7
  XPerl, v3.0.2a
  XPerlArcaneBar, v
  XPerlCustomHighlight, v
  XPerlParty, v
  XPerlPartyPet, v
  XPerlPlayer, v
  XPerlPlayerBuffs, v
  XPerlPlayerPet, v
  XPerlRaidAdmin, v
  XPerlRaidFrames, v
  XPerlRaidHelper, v
  XPerlRaidMonitor, v
  XPerlRaidPets, v
  XPerlTarget, v
  XPerlTargetTarget, v
  (ck=e2b)