[Yaffs] ecc error unfixed on chunk

Good day dear All.

I've installed latest yaffs and latest mtd from CVS and receive some (not
some, a lot of) next error messages:

**>>ecc error unfixed on chunk 32:0
**>>ecc error unfixed on chunk1 32:1

for a lot of chunks. These errors I've received just at the mount
procedure, or when I'm trying to do, for example, ls.

I have no such problems with previous yaffs and mtd versions.

Also I have a short look on sources, and this error messages comes from

yaffs_ReadChunkFromNAND function (yaffs_tagscompat.c)

else if(nspare.eccres2<0) {
T(YAFFS_TRACE_ERROR,(TSTR("**>>ecc error unfixed on chunk1 
%d:1\n"),chunkInNAND));
                }

at error case both nspare.eccres2 and nspare.eccres1 equivalent to -1.

I try to compared with previous versions, and
nspare.eccres2==nspare.eccres1==0 for chunk 32.

Please, can you help and explain me, where is this problem could be?

Thank you.