WowAce

What steps will reproduce the problem?
1. Not really sure. Seems to be a bit random but I mouse over some items and the error pops up, others it doesn't seem to do it with.
2.
3.

What is the expected output? What do you see instead?
Nothing is expected at this time. I am not attempting to compare items it just errors out when I mouse over some specific items. This occured when I was mousing over a peice of heirloom gear in my mailbox.

What version of the product are you using?
1.6.7

Do you have an error log of what happened?

Please provide any additional information below.
Date: 2013-04-24 10:17:12
ID: 1
Error occured in: Global
Count: 1
Message: ...ingBuster\libs\LibStatLogic-1.2\LibStatLogic-1.2.lua line 9967:
   attempt to index field '?' (a nil value)
Debug:
   [C]: ?
   ...ingBuster\libs\LibStatLogic-1.2\LibStatLogic-1.2.lua:9967:
      ...ingBuster\libs\LibStatLogic-1.2\LibStatLogic-1.2.lua:9944
   (tail call): ?
   RatingBuster\RatingBuster.lua:2547: handler()
   ...ingBuster\libs\LibTipHooker-1.1\LibTipHooker-1.1.lua:179:
      ...ingBuster\libs\LibTipHooker-1.1\LibTipHooker-1.1.lua:174
   [C]: SetInboxItem()
   ..\FrameXML\MailFrame.lua:765: OpenMailAttachment_OnEnter()
   [string "*:OnEnter"]:1:
      [string "*:OnEnter"]:1
Locals:

AddOns:
  Swatter, v5.16.5405 (MousyMulgara)
  Ace3, v
  Altoholic, v5.2.001
  ArkInventory, v30327
  ArkInventoryRules, v
  AtlasLootLoader, vv7.05.03
  AucAdvanced, v5.16.5405 (MousyMulgara)
  AucFilterBasic, v5.16.5405 (MousyMulgara)
  AucFilterOutlier, v5.16.5405.5347(5.16/embedded)
  AucMatchUndercut, v5.16.5405.5364(5.16/embedded)
  AucScanData, v5.16.5405 (MousyMulgara)
  AucStatHistogram, v5.16.5405 (MousyMulgara)
  AucStatiLevel, v5.16.5405 (MousyMulgara)
  AucStatPurchased, v5.16.5405 (MousyMulgara)
  AucStatSales, v5.16.5405.5376(5.16/embedded)
  AucStatSimple, v5.16.5405 (MousyMulgara)
  AucStatStdDev, v5.16.5405 (MousyMulgara)
  AucStatWOWEcon, v5.16.5405.5323(5.16/embedded)
  AucUtilAHWindowControl, v5.16.5405.5347(5.16/embedded)
  AucUtilAppraiser, v5.16.5405.5393(5.16/embedded)
  AucUtilAskPrice, v5.16.5405.5347(5.16/embedded)
  AucUtilAutoMagic, v5.16.5405.5392(5.16/embedded)
  AucUtilCompactUI, v5.16.5405.5400(5.16/embedded)
  AucUtilEasyBuyout, v5.16.5405.5347(5.16/embedded)
  AucUtilFixAH, v5.16.5405 (MousyMulgara)
  AucUtilItemSuggest, v5.16.5405.5365(5.16/embedded)
  AucUtilPriceLevel, v5.16.5405.5365(5.16/embedded)
  AucUtilScanButton, v5.16.5405.5403(5.16/embedded)
  AucUtilScanFinish, v5.16.5405.5347(5.16/embedded)
  AucUtilScanProgress, v5.16.5405.4979(5.16/embedded)
  AucUtilScanStart, v5.16.5405.5347(5.16/embedded)
  AucUtilSearchUI, v5.16.5405.5373(5.16/embedded)
  AucUtilSimpleAuction, v5.16.5405.5388(5.16/embedded)
  AucUtilVendMarkup, v5.16.5405.4828(5.16/embedded)
  Babylonian, v5.1.DEV.332(/embedded)
  Bartender4, v4.5.9
  BeanCounter, v5.16.5405 (MousyMulgara)
  Carbonite, v5.1.6
  CarboniteTransfer, v1.01
  Configator, v5.1.DEV.344(/embedded)
  DataStore, v5.2.001
  DataStoreAchievements, v5.2.001
  DataStoreAgenda, v5.2.001
  DataStoreAuctions, v5.2.001
  DataStoreCharacters, v5.2.001
  DataStoreContainers, v5.2.001
  DataStoreCrafts, v5.2.001
  DataStoreCurrencies, v5.2.001
  DataStoreInventory, v5.2.001
  DataStoreMails, v5.2.001
  DataStorePets, v5.2.001
  DataStoreQuests, v5.2.001
  DataStoreReputations, v5.2.001
  DataStoreSpells, v5.2.001
  DataStoreStats, v5.2.001
  DataStoreTalents, v5.2.001
  DBMCore, v
  DBMLDB, v
  DBMRaidLeadTools, v
  DebugLib, v5.1.DEV.337(/embedded)
  Decursive, v2.7.2.8
  Enchantrix, v5.16.5405 (MousyMulgara)
  EnchantrixBarker, v5.16.5405 (MousyMulgara)
  Gatherer, v4.2.0
  GearScore, v5.2.0
  HealBot, v5.2.0.4
  HealBotTips, v5.2.0.2
  Informant, v5.16.5405 (MousyMulgara)
  LibExtraTip, v5.12.DEV.350(/embedded)
  Omen, v3.1.8
  Postal, v3.5.1
  QuestAnnounce, v5.2.0
  RatingBuster, v1.6.7
  Recount, v
  SlideBar, v5.16.5405 (MousyMulgara)
  Stubby, v5.16.5405 (MousyMulgara)
  TipHelper, v5.12.DEV.343(/embedded)
  WIM, v3.6.7
  XPerl, v3.6.35
  XPerlArcaneBar, 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
  BlizRuntimeLib_enUS v5.2.0.50200 <us>
  (ck=beb)

Version 1.6.7 is for WoW 4.3.4. Use the latest Alpha version for WoW 5.2.