Hi,

> Writing, reading and erasing files works, until I umount and mount
> filesystem. df still states correct filesystem usage, however only
> directory visible is lost+found. All files are gone.

Same story here. AFAIK yaffs2 has problems with newer mtd oob autoplacement. 
See Nick's post. I see the same 16 bit shift in oob data. There was mtd fix 
(autoplace_user flag) and it was supposed to correct that but I could not seem 
to make it work either.

Let me know if you manage to get it working..

Nick, did you manage to get it going with user autoplace?

Sergei Sharonov