Paul, please check with your examiner that you were given the amended exam, if you weren't then you started off with more chance of failing than passing and he/she is the one who has made the mistake and should rectify the situation. At the very least you should have that one voided, (assuming you have been given the wrong paper that is.) I failed that paper by one mark and that was what set the alarm bells ringing with the examiner. If I remember correctly there were three wrong answers and one question on something not included in the PPL syllabus on that paper so you set off with a disadvantage of 20% before you had even started and that left only one question leeway.
I have been at my school for a while and I convinced that they are a well ordered, well run school. So I'm sure I was given the correct paper, just one of those things.
Can't wait till I'm flying for real and come across a MATZ, I will divert left straight away