That's absolutely great - thank you so much!
I have done as you said above, and the only other change required was to comment out @top_includelets@ and the conditional @title@ display.
No other changes were necessary, which is fantastic, because that means that no 'core' files have had to be changed.
I still wonder though, how could you ever return a complete HTML document to IE using ?master=0 (which I agree could be very useful) if the content gets wrapped in a div block?
Regards,
Richard.