I'm trying to enable TLS on Postfix but the daemon is crashing:

Sep 16 16:00:38 core postfix/master[1689]: warning: process /usr/libexec/postfix/smtpd pid 1694 killed by signal 11
Sep 16 16:00:38 core postfix/master[1689]: warning: /usr/libexec/postfix/smtpd: bad command startup -- throttling

CentOS 6.3 x86_64

# postconf -n
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
broken_sasl_auth_clients = yes
command_directory = /usr/sbin
config_directory = /etc/postfix
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
debug_peer_level = 2
disable_vrfy_command = yes
home_mailbox = Maildir/
html_directory = no
inet_interfaces = all
inet_protocols = all
local_recipient_maps = 
mail_owner = postfix
mailbox_command = 
mailq_path = /usr/bin/mailq.postfix
manpage_directory = /usr/share/man
mydestination = $myhostname, localhost.$mydomain, localhost
mydomain = domain.com
myhostname = mail.domain.com
mynetworks = 127.0.0.0/8
myorigin = $mydomain
newaliases_path = /usr/bin/newaliases.postfix
queue_directory = /var/spool/postfix
readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
relay_domains = 
sample_directory = /usr/share/doc/postfix-2.6.6/samples
sendmail_path = /usr/sbin/sendmail.postfix
setgid_group = postdrop
smtp_tls_note_starttls_offer = yes
smtp_tls_session_cache_database = btree:/var/lib/postfix/smtpd_tls_cache.db
smtp_use_tls = yes
smtpd_delay_reject = yes
smtpd_error_sleep_time = 1s
smtpd_hard_error_limit = 20
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks,    reject_non_fqdn_hostname,   reject_invalid_hostname,    permit
smtpd_recipient_restrictions = permit_mynetworks,   permit_sasl_authenticated,  reject_unauth_pipelining,   reject_non_fqdn_recipient,  reject_unknown_recipient_domain,    reject_invalid_hostname,    reject_non_fqdn_hostname,   reject_non_fqdn_sender, reject_unknown_sender_domain,   reject_unauth_destination   reject_rbl_client cbl.abuseat.org,  reject_rbl_client bl.spamcop.net,   permit
smtpd_sasl_auth_enable = yes
smtpd_sasl_local_domain = $myhostname
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_sender_restrictions = permit_mynetworks,  reject_non_fqdn_sender, reject_unknown_sender_domain,   permit
smtpd_soft_error_limit = 10
smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
smtpd_use_tls = yes
tls_random_source = dev:/dev/urandom
unknown_local_recipient_reject_code = 550