ok so this is the problem
looks like faulty card, or some problem in mmc driver, i think sector is 512bytes so the number it wants is ok (beginnning of second partition where ext2 superblock should be). You can try flashing back original nokia kernel if it makes a difference. Also try (with both kernels) to read whole card via 'dd if=/dev/mmcblk0 of=/dev/null bs=512' and see kernel log for i/o errors of bad blocks. This may take a while. You may run 'tail -f /proc/kmsg' to watch log at runtime. If you still have i/o errors no matter what, you can try to reformat the card with Panasonic SD formatter.