error in swift-init proxy start command

I'm following the instruction in http://swift.openstack.org/howto_installmultinode.html

Inside /etc/swift/proxy-server.conf

[DEFAULT]
cert_file = /etc/swift/cert.crt
key_file = /etc/swift/cert.key
bind_port = 8080
workers = 8
user = swift

[pipeline:main]
pipeline = healthcheck cache tempauth proxy-server

[app:proxy-server]
use = egg:swift#proxy
allow_account_management = true

[filter:tempauth]
use = egg:swift#tempauth
user_system_root = testpass .admin https://$PROXY_LOCAL_NET_IP:8080/v1/AUTH_system

[filter:healthcheck]
use = egg:swift#healthcheck

[filter:cache]
use = egg:swift#memcache
memcache_servers = $PROXY_LOCAL_NET_IP:11211

The rest of the commands were running fine, until I encounter this..

enteng@cloud1:/etc/swift$ sudo swift-init proxy start
[sudo] password for enteng:
Starting proxy-server...(/etc/swift/proxy-server.conf)
Traceback (most recent call last):
  File "/usr/bin/swift-proxy-server", line 22, in <module>
    run_wsgi(conf_file, 'proxy-server', default_port=8080, **options)
  File "/usr/lib/python2.7/dist-packages/swift/common/wsgi.py", line 118, in run_wsgi
    sock = get_socket(conf, default_port=kwargs.get('default_port', 8080))
  File "/usr/lib/python2.7/dist-packages/swift/common/wsgi.py", line 84, in get_socket
    bind_addr)
Exception: Could not bind to 0.0.0.0:8080 after trying for 30 seconds

Please help! Thanks!