[Arm-netbook] A10 MMC Boot Instructions

[cnxsoft]

I previously followed the instructions given on 
http://rhombus-tech.net/allwinner_a10/a10_mmc_boot/ with a particular SD 
card and it worked fine.

But now, the partition tablet will be wiped out.

When I create the partitions as follows:

# sudo fdisk -lu /dev/sdb
GNU Fdisk 1.2.4

Disk /dev/sdb: 3 GB, 3956359680 bytes
255 heads, 63 sectors/track, 481 cylinders, total 7727265 sectors
Units = sectors of 1 * 512 = 512 bytes

    Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048       34815       24066   83  Linux
Warning: Partition 1 does not end on cylinder boundary.
/dev/sdb2           34816     7727264     3839535   83  Linux

and write some data at the u-boot spl offset:

# sudo dd if=/dev/zero of=/dev/sdb bs=1024 skip=8 count=1
1+0 records in
1+0 records out
1024 bytes (1.0 kB) copied, 0.127269 s, 8.0 kB/s

It will wipe out the partition table:

# sudo fdisk -lu /dev/sdb
GNU Fdisk 1.2.4

Disk /dev/sdb: 3 GB, 3956359680 bytes
255 heads, 63 sectors/track, 481 cylinders, total 7727265 sectors
Units = sectors of 1 * 512 = 512 bytes

    Device Boot      Start         End      Blocks   Id  System

Has anybody experience this issue? Is there a way to resolve it apart 
from buying a new SD card ?
I've upgrade from Ubuntu 10.04 to Ubuntu 12.04 between the 2 tests in 
case it's relevant.

Thanks.