xferlog is not getting written for all file transfers

Hi,
 
For whatever reason, /var/log/xferlog file is not getting written with
all file transfers.  Just today, there are a few missing records for
those file transfers that actually took place.  Below is how I have
configured the ftpaccess file.  Has anyone experienced this problem
before?
 
########################################################################
#######
# Redirects the logging messages for incoming and outgoing transfers to
#
# syslog. Without this option the messages are written to xferlog.
#
# syslog+xferlog sends the transfer log messages to both the system log
and   #
# the xferlog.
#
########################################################################
#######
log syslog
log syslog+xferlog
 
Peter Loo
Banner Health