preserve owner when owner is the only change

[Arnaud DUBARRY]

Hello,

I'm trying to make incremental backups with rsync (I'm reading 
http://www.mikerubel.org/computers/rsync_snapshots/ )
But I can't backup a file with old owner when the change on the file is 
only the owner (content is unchanged).

rsync -av -e ssh --link-dest=$PWD/backup.1/ --numeric-ids --delete 
root at myhost.mydomaine.org:/var/www backup.0

If I look at the owner of $PWD/backup.1/test-file (it's an exemple), 
it's always link to backup.0/test-file, so the old owner is lost.

I'm using rsync  version 2.6.4  protocol version 29 (on debian sarge)

Is it a normal behavior of rsync ?

Thank you by advance,

Arnaud Dubarry