Paul,
Once upon a time the CASA pass mark was 80%. Maybe you were in this group. After such a low pass rate at that time, the people in Canberra thought 70% was a better way to go. It has been 70% ever since.
I really believe they should base the exam on an actual flight plan, with questions in the sequence of what you would actually do on the day as a pilot.
PM for the other info.
Paul please don't give up, it does feel so goood when you crack the jackpot........