I was asked to upgrade to premium again when I logged in today.

Your recurring subscription may have been canceled by our system because of a failed/declined payment. Sometimes US banks will mistakenly trigger declines when receiving a request from a foreign bank (our payment processor is Verotel - based in the Netherlands). You may try calling your bank directly to ensure that the payment can be authorized from Verotel/SP. Then try again to upgrade via your SP settings page.