I've just made 2.6.29 and yaffs-beginning-of-march the default in
ballon SVN so it would be good to try and get to the bottom of this.
Noodles saw something very similar but put it down to building loads
of different kernels/yaffs variants and accidentally doing something
bad, but now we have two instances that suggests a more significant
issue.

After comparing and debugging various builds I believe this issue lies with the mtd nand driver and not yaffs.
Since this looks like a board specific Balloon/mtd driver issue, I will post further details on the Balloon ML.

Jim