QUOTE(Maizie @ Nov 4 2008, 08:34 AM)

Which goes to show you're not the first person to do this, and you certainly won't be the last. It must actually be pretty common, so much so that AB have a standard way of dealing with it (i.e. warning letter). I'm guessing if you do it again they might not be so understanding

THis happenned to me once as an accompanist where the trumpet teacher hadn't spotted a couple of pieces that hadn't made it through a syllabus revision, so had done the list B piece from the previous list. A genuine mistake and the board acknowledged that. The examiner didn't make a big deal about it, he just noted the piece and sent a letter on afterwards.
However, many years ago when I did my grade 4 organ, I had been learning a Prelude by William Harris, which my teacher discovered was the wrong one, abouyt 4 days before the exam. In those days, when the AB was a little less user friendly, I had to learn the new piece in double quick time.