"....you may remember the instructor who crashed a Baron ( I think) near Canberra enroute to the snow from Bankstown some 15yrs ago due to not allowing for the COG movement with the fuel burn off."
I apologise for the thread drift, but.....
While I recall this accident, I can't recall the outcome of the crash investigation. If someone can point me to the ASTB report, I would like to read it.
I haven't flown a Baron for a few years but I suspect CofG issues with a Baron are likely to be similar to the Bonanza. If that is the case then it is unlikely this accident was caused solely by a failure to allow for fuel burn in the CofG calculations. It is most likely that the aeroplane was overloaded to start with.
While it is true that in the Bonanza, fuel burn off results in a rearward movement of the CofG, this is largely compensated for by CofG envelope.
If the aeroplane is within the CofG envelope when you start the flight - it will be within the the envelope at the end of the flight - except if you are operating with minimum fuel.
Dr 
Sorry - this has little to do with the thread, but is an attempt to correct the misconception that in the Bonanza/Baron (I suspect), fuel burn will take you out the back of the CofG envelope.