nilfs_sync_super: barrier sync FAILS

Hi;
The moment when NILFS dies (a horrible death :-) with "I/O error -> Disk Full",
the log:
segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
NILFS warning (device dm-10): nilfs_sync_super: barrier sync failed. disabling barriers
...
...
fatal I/O error: no space left on device
Any ideas? (Rolling back works!!! -> nilfs .12 module + utils .12 + 2.6.27.8 kernel -> no problems.)
Cheers