UBI error: nor_erase_prepare: cannot invalidate PEB 76, write returned -5 read returned 2

[Alexander Stein]

Hello,

I'm observing the given error after starting Linux. ubiattach is called from 
within the init-script. Currently I'm running v2.6.34. The filesystem is 
mounted read-only as expected.
It gets curious that afterwards in u-boot the corresponding sector is complety 
empty, read 0xff. It seems the sector cannot be written, although it is empty.
Has anybody an idea about such phenomenon? Oh, before it forget, I use a 
Numonyx Axcell M29EW NOR-Flash 128MiB.

Best regards
Alexander