vsftpd with ssl - vsftpd.user_list not working

hi there...

i've successfully set up a vsftpd server with ssl running on debian
sarge. but the userlist_enable=YES does not realy work! user "sysadmin"
is able to log in but he isn't listed in /etc/vsftpd.user_list!

here's my server config:

# FTP SETTINGS
write_enable=YES
download_enable=YES
ascii_download_enable=YES
ascii_upload_enable=YES
dirlist_enable=YES
dirmessage_enable=NO
hide_ids=YES
pasv_enable=YES

# LOGGING
log_ftp_protocol=YES
xferlog_enable=YES

# SSHL SETTINGS
ssl_enable=YES
ssl_tlsv1=YES
ssl_sslv2=YES
ssl_sslv3=YES
rsa_cert_file=/etc/ssl/certs/vsftpd.pem
force_local_logins_ssl=YES
force_local_data_ssl=YES

# LISTEN SETTINGS
listen=YES
listen_address=80.*.*.*
listen_port=21
listen_ipv6=NO
max_clients=5
max_per_ip=3
connect_from_port_20=YES

# USER MANAGEMENT
secure_chroot_dir=/var/run/vsftpd
userlist_deny=NO
userlist_enable=YES
userlist_file=/etc/vsftpd.user_list
user_config_dir=/etc/vsftpd_user_conf
chroot_list_file=/etc/vsftpd.chroot_list
chroot_list_enable=YES
chroot_local_user=YES
anon_world_readable_only=NO
anonymous_enable=NO
local_enable=YES
pam_service_name=vsftpd
nopriv_user=ftpsecure

any ideas?

thanks,
christof