rsync snapshot problem deleting files

[Mark L. Chang]

Well, I followed this link: 
http://www.mikerubel.org/computers/rsync_snapshots/

and implemented it (with a bit of tweaking) on my home network. It is 
used to make snapshots of two Windows PC's over samba. On one of the 
machines (and not the other, from what I can tell) it deletes files from 
the target machine for no good reason (ie. they still exist on the 
source machine). Then, if I run it again right away, it gets the files anew.

Most is the same as Mike's script, here is the relevant rsync:
$RSYNC -va --delete --delete-excluded
   --exclude-from="$EXCLUDES" --stats $BACKUPMOUNT/ \
   $SNAPSHOTDIR/$SHARE/snap.0 > $BACKUPDIR/${BACKUPHOST}.output 2>&1 ;

: excludes :
RECYCLER/
System Volume Information/

: mounted drive ($BACKUPMOUNT) is :
$MOUNT -o ro -t smbfs //$BACKUPHOST/$SHARE $BACKUPMOUNT -o 
username=$USERPASS ;

And here, from my log of the output, from two back-to-back runs without 
modifying the source drive:
[first run]
deleting code/research/octave-2.0.16/kpathsea/kpsewhich.c
   -- deletes the file, and doesn't re-get it, leaving that snapshot 
without this file

[second run]
code/research/octave-2.0.16/kpathsea/kpsewhich.c
   -- fetched the file, as it really exists on the source drive but not 
in my snapshot system

What is going on? Obviously, this type of deleting stuff randomly is not 
good for my hot backup scheme.

Mark