Just had a look through the stuff related to 'Mungo Man' on Wikipedia etc. And, yes, the range of dates that have been attributed to the specimens are very wide and don't always agree with each other. But this doesn't 'prove' anything, pete - it just means that, in this particular example, there are some anomalies which need to be resolved (I'm sure that there are examples where there are good agreements on dates). And remember, if the science is all wrong, wrong, wrong (which I very much doubt) it still doesn't make your preferred biblical chronology right!