I can not get the relevant [model] number from any order to come up in the script on checkout page so that it applies campaign by product ID.
Source code on checkout completetion page for a dummy order refferred by afiliate link as follows:

var sale = PostAffTracker.createSale();
sale.setTotalCost('US$0.06');
sale.setOrderID('3587');
sale.setProductID('[model]');
PostAffTracker.register();

It picks up everything else as you can see above but just not the model number - anyone know why? I have items itemised on my PayPal checkout so that PayPal records the item number too.