What steps will reproduce the problem?
No way to reproduce it that I know of. It was random while I was standing in Stormwind. Possibly triggered when I hovered over a horde tauren, but I don't think so.

What is the expected output? What do you see instead?
Um.. nothing?

What version of the product are you using?
1.12-144
date: 2008-10-18

Do you have an error log of what happened?

Date: 2008-10-20 21:16:27
ID: 52
Error occured in: Global
Count: 1
Message: ..\AddOns\Cartographer_Vendors\addon.lua line 517:
   attempt to index global 'Cartographer_Notes' (a nil value)
Debug:
   [C]: ?
   Cartographer_Vendors\addon.lua:517 in main chunk
AddOns:
  Swatter, v5.1.3655 (SnaggleTooth)
  AckisRecipeList, v0.9372
  Altoholic, v3.0.002b
  ArkInventory, v3.01
  AucAdvanced, v5.1.3655 (SnaggleTooth)
  AucFilterBasic, v5.1.3655 (SnaggleTooth)
  AucFilterOutlier, v5.1.3655.2531
  AucMatchUndercut, v5.1.3655.2531
  AucStatClassic, v5.1.3655 (SnaggleTooth)
  AucStatHistogram, v5.1.3655 (SnaggleTooth)
  AucStatPurchased, v5.1.3655 (SnaggleTooth)
  AucStatSales, v5.1.3655.2842
  AucStatSimple, v5.1.3655 (SnaggleTooth)
  AucStatStdDev, v5.1.3655 (SnaggleTooth)
  AucStatWOWEcon, v5.1.3655.2530
  AucUtilAHWindowControl, v5.1.3655.3311
  AucUtilAppraiser, v5.1.3655.2530
  AucUtilAskPrice, v5.1.3655.3175
  AucUtilAutoMagic, v5.1.3655.3142
  AucUtilCompactUI, v5.1.3655.2530
  AucUtilEasyBuyout, v5.1.3655.3583
  AucUtilItemSuggest, v5.1.3655.3108
  AucUtilPriceLevel, v5.1.3655.2545
  AucUtilScanButton, v5.1.3655.2530
  AucUtilScanFinish, v5.1.3655.2530
  AucUtilScanProgress, v5.1.3655.2530
  AucUtilSearchUI, v5.1.3655.3483
  AucUtilVendMarkup, v5.1.3655.2530
  Auditor2, v3.2.1
  AuldLangSyne, v2.0
  Babylonian, v5.1.DEV.130
  BeanCounter, v5.1.3655 (SnaggleTooth)
  Bejeweled, v1.02
  ButtonFacade, v0.1Alpha
  ButtonFacadeTrinity, v30000.1
  Cartographer, v2.0
  CartographerTrainers, v20400.3
  CartographerVendors, v20400.2
  Configator, v5.1.DEV.130
  DebugLib, v5.1.DEV.130
  EnhTooltip, v5.1.3655 (SnaggleTooth)
  FuBar, v
  ItemRack, v
  Skillet, v
  Stubby, v5.1.3655 (SnaggleTooth)
  (ck=5a5)

Please provide any additional information below.

small posted at curse.