i met the similar issue on the s3c6410 board,it should be the yaffs2 fs code issue in your kernel(the kernel code on the offical google website,I think).
what you should do is just download the latest yaffs2 code from the offical website (not google website) and replace the yaffs2 code in your kernel.

rebuild your kernel and tested it.

it should give you a suprise!

and it spent more than two days on solving  this issue and it  works for me now.
I think the latest yaffs2 code  on the offical website has solved this issue.
Hope this can help you!