Would have been nice to have a proper error message like "Purchase failed because there's no SIM card and therefore we don't know who to bill. Please insert a SIM card or add a credit card number to your OVI account and try again". Tyranny of the SIM card and tyranny of the carriers all in one!
I will add a credit card number to my OVI account and try again and post a blog post on what I find. (hopefully not a case of the #maplesyrupcurtain :-) !)