I was sure I had set that to true previously and it still didnt work!
I've just tried again and voila, its all good!
It may not have worked originally as I was doing something weird with the modal datasource - Where as for this test everything is on one page as you suggested.
Next step is to get it all back into a modal and see if I get the same result.
Thanks again for your help, I'll confirm soon how I get on with calling things via the modal