Exchange 2010 - Offline Addressbook

I don't think I'm going crazy but cant find out why this is happening?

When I search the Address book in cached mode (OAB) in outlook for "Jackie W" I get a number of users which include "Jackie W***" but some are "Jackie K***" or "Jackie B***" but their Office is set to "Westminster"

But this is the strange part when I search on the address book with Cached mode disabled (GAL) I only get users with Surnames begging with "W" so only "Jackie W***" show up and if I just type in "Westminster" I get users form that location! but not a mix like on the OAB!

To my knowledge the OAB is just a Copy of the GAL and should be the same and pull up the same information when searching is this correct or am I going crazy! :D