Is DoC2000's nftla possibly write protected ?

[Ralf Spachmann]

All,

according to the jffs howto, I nftl_formatted the DOC2000
I insmod the nftl.o and the partition check issues 
'unknown partition table' 
So I want to fdisk the /dev/nftla, create my partitions but
on the 'w' it complains :  'Unable to write /dev/nftla'

What's wrong ?

TIA 
Ralf