Just a tiny tip for folks using NPCScan. Deleting your cache manually is pain in the arse, so I've made a little .bat file that does that for me each time I start my computer. Here's a short guide how to do it:
1.Open your Notepad. Paste the code below in it:
@echo off
del Cache\WDB\enGB\creaturecache.wdb
OR if you're playing in the US region:
@echo off
del Cache\WDB\enUS\creaturecache.wdb
Save it as a .bat file - I've named my startup.bat.
2.Move your startup.bat file into WoW main catalogue.
3.Right click the file and use Send to --> Desktop (create shortcut) (or whatever is it called in english, you get the idea).
4.Go to your desktop, locate the file, right click it and pick Copy.
5.Open your Start bar and go into programs menu. Locate the 'Startup' catalogue there, right click on it and choose 'open'.
6.Right click anywhere in the catalogue and pick 'Paste'.
7.Profit
It saved me a shitloads of time, and made me a couple of nice rare items/gold (and one mount!). The best thing is with that setup you don't have to ever do anything more - your cache is cleaned each time you restart your system. You can of course use the startup.bat manually to clean the cache BUT your WoW can't be running at the time!