Finally! yesterday I did my first backup and it seems ok, but I've some doubts 
about various messages:

FAILURE AND STRANGE DUMP SUMMARY:
  xaloc      /dev/sdc2 lev 0 STRANGE

....

FAILED AND STRANGE DUMP DETAILS:

/-- xaloc      /dev/sdc2 lev 0 STRANGE
sendbackup: start [xaloc:/dev/sdc2 level 0]
sendbackup: info BACKUP=/bin/tar
sendbackup: info RECOVER_CMD=/bin/gzip -dc |/bin/tar -f... -
sendbackup: info COMPRESS_SUFFIX=.gz
sendbackup: info end
? gtar: ./notesdata/mail/sdelamoc.nsf: file changed as we read it
? gtar: ./notesdata/mail/spaxtonl.nsf: file changed as we read it
? gtar: ./notesdata/mail/xguardio.nsf: file changed as we read it
| Total bytes written: 4793784320 (4.5GB, 3.3MB/s)
sendbackup: size 4681430
sendbackup: end
\--------

I've looked at the index files of  _dev_sdc2 and the list seems to be ok. Then 
I suppose the mentioned users was connected ( from home) when amanda did the 
backup (0:45). It seems, true? 

No problem with the rest of filesystems ( or it seems ).

Best Regards,

Raúl
rcruz AT wild-spain DOT com