Hmmm, looks like I may have used the inccorect divis as it seems it should be teh average of all slections, not just winners. In this case the av divis should be:

Betafair:5.79 (raw price)
SuperTAB:5.04

Using the supertab price I get a Chitest score of:

0.000546

This seems far to small though so am thinking I have stuffed up somewhere.