backup level

Hi,

I can't find enough information about the backup levels.
level 0 is a full backup. what other levels do exist and what does which 
level backup when the argument -wtardumps is defined?

I created a snapshot of a logical volume (mounted as /) and mounted it 
to /mnt/snap. Then i created a full backup which finished successfully.
After the first full backup i deleted the snapshot and recreated it and 
did another full backup. This time star prints that it is a partial dump 
and created an empty archive.

File system /
Working dir /mnt/snap
Dumptype    partial
Dumplevel   0
Dumpdate    1200517143.000000 (Wed Jan 16 21:59:03 2008)
Volno       1
Blocksize   20
       0 drwxr-xr-x   2 root/nobody Jan 15 23:41 2008 ./
star: 1 blocks + 0 bytes (total of 10240 bytes = 10.00k)


I thought star would backup the hole snapshot again because i used level=0.
Do i have a logic problem or is this a problem with this old release?

regards,
Thomas Antony