My shipping stats with nds-card.com:
ordered 5th December. Arrived 8thDecember by DHL
ordered 17th December using HongKong Post. Arrived 27th December.
Country: Malta, Europe
Most probably the "C" cards with metroid icon are no "C" at all! They are re-badged "B" cards.
Fortunately I bought them from nds-card.com who kindly replaced them for me
same problem here. New card rev C with metroid icon bought from nds-card last week.
Neither file works.
8gb Sandisk card with R4ids.cn card on a nintendo 3ds with V 1.1.0-0E firmware.