QUOTE(DawnF @ Jan 20 2010, 10:08 PM)

Do I
need to think in both variants or just recognise that if i'm asked to play Cb major I play the scale or whatever of B major?

Nope, I don't think you do. I have Db major as one of my 'current' scales, and my teacher said 'oh, it's not that bad, it's just C# major'. Which I suppose was meant to be helpful

But he said just to think of whichever one is easiest for me.
Indeed, on the G6 syllabus TG actually say "G#/Ab minor (one octave)" - so I suppose the examiner could ask for 'either', and if the examiner said G# but you actually played Ab, how would the examiner know the difference?