Thought i'd add, i checked my book tonight for a similar type question and to my delight i found one.
This confuser also gives you a reason to the answer....
It also added the difference between aerodrome altitude above amsl to the difference between the QFE and the standard 1013....
Now, im trying to understand why.
It's basically saying the pressure altitude is the aerodrome altitude above amsl plus the difference between QFE and 1013...
I cant get this wrong in the test, so I need to know for sure what is right.. What am I to believe... 2 sources which give the same answer, 1 of which gives a reason why, or PPRUNE?