Some files vanished...

[lewis butler]

I run an rsync to backup my mail server ever 4 hours.  Sometimes, I  
get these sorts of warnings:

Rsyncing...
file has vanished: "/usr/local/virtual/*munged1*/new/ 
1210876129.43402_0.mail.server.tld"
file has vanished: "/usr/local/virtual/*munged2*/courierimapkeywords/. 
4036254.1210876052.43312_0.mail.server.tld"
file has vanished: "/usr/local/virtual/*munged3*/cur/ 
1210869474.40181_0.mail.server.tld:2,"
file has vanished: "/usr/local/virtual/*munged3*/new/ 
1210875706.43197_0.mail.server.tld"

Number of files: 845497
Number of files transferred: 514
Total file size: 24.61G bytes
Total transferred file size: 3.09G bytes
Literal data: 3.09G bytes
Matched data: 0 bytes
File list size: 22384273
File list generation time: 447.621 seconds
File list transfer time: 0.000 seconds
Total bytes sent: 3.12G
Total bytes received: 511.24K

sent 3.12G bytes  received 511.24K bytes  2.22M bytes/sec
total size is 24.61G  speedup is 7.89
rsync warning: some files vanished before they could be transferred  
(code 24) at main.c(977) [sender=2.6.9]
...done.

the rysnc command is

/usr/local/bin/rsync -aCHh --stats --delete-after --delete-excluded \
     --exclude="/backup/" --exclude-from=/var/.rexcludes \
     --link-dest="${BAKLOC}.sday.1" / ${BAKLOC}.sday.0

where BAKLOC is defined previously to /backup/mail

Is there anything I can do to have rsync work on a instantaneous  
snapshot so these files don't even up getting moved out from under the  
backup process?

This is 2.6.9 and I am not in a position to upgrade to 3.0 right now.