Question about a problemFollow

Ok, so before the new patch came out I was playing WoW on my laptop instead of desktop. Instead of re-installing it on my laptop, I put the files on my iPod and transferred them over to my laptop, it was much faster than installation and everything worked fine.
Yesterday I get the patch but I needed it on the desktop so I download it for my desktop, run the blizzard updater, then run it and it works. Then i copied all of the NEW files with the patch updated etc. back to my laptop, and when I run it I get this

This application has encountered a critical error:

ERROR #121 (0x85100079) Version Mismatch
Program: G:\World of Warcraft\WoW.exe

DBFilesClient\AreaTable.dbc has wrong number of columns (found 25, expected 27)


WoWBuild: 6180

By the way that was running it off my Ipod, im actually running it off the laptop copied into a folder.

I dont understand this, it didn't do this before