Bit of a shot in the dark here. I've got hold of a blue cover, developer edition, Shield with an old firmware. I've tried to update to retail firmware, but it has issues with emulated/0 not existing. Due to not having a physical sdcard, the mounts seem to be set up a bit differently.
Does anyone know where the developer updates would be available? Or failing that, any easy way of mounting an sdcard on a non-rooted Shield?