configuring FlatManager & injecting IP address

I'm trying to setup FlatManager network, below is the nova.conf file...

--dhcpbridge_flagfile=/etc/nova/nova.conf
--dhcpbridge=/usr/bin/nova-dhcpbridge
--logdir=/var/log/nova
--state_path=/var/lib/nova
--lock_path=/var/lock/nova
--flagfile=/etc/nova/nova-compute.conf
--force_dhcp_release=True
--use_deprecated_auth
--verbose
--s3_host=127.0.0.1
--rabbit_host=127.0.0.1
--cc_host=127.0.0.1
--ec2_url=http://127.0.0.1:8773/services/Cloud
--fixed_range=10.0.0.0/24
--network_size=255
--FAKE_subdomain=ec2
--routing_source_ip=10.0.0.2
--verbose
--sql_connection=mysql://root:xxxx@127.0.0.1/nova
--network_manager=nova.network.manager.FlatManager
--flat_interface=eth1
--public_interface=eth0
--flat_network_bridge=br100
--network_host=127.0.0.1
--connection_type=vmwareapi
--vmwareapi_host_ip=10.0.0.2
--vmwareapi_host_username=root
--vmwareapi_host_password=xxxxxxxxx
--vmwareapi_wsdl_loc=http://127.0.0.1:8080/wsdl/vim25/vimService.wsdl
--glance_api_servers=127.0.0.1:9292
--image_service=nova.image.glance.GlanceImageService
--iscsi_ip_prefix=10.0.

i'm using ubuntu 11.04 natty server with diablo.

image file is VMDK file.

my problem is that IP address is not getting injected into created instance.. please help to solve this issue.