in flat network mode ip not get injected

nova-compute log
2011-08-09 04:36:19,782 nova.compute.disk: aug_get: no matching node
(nova.compute.disk): TRACE: Traceback (most recent call last):
(nova.compute.disk): TRACE: File "/usr/lib/python2.6/site-packages/nova/virt/disk.py", line 81, in inject_data
(nova.compute.disk): TRACE: devices = g.inspect_os()
(nova.compute.disk): TRACE: File "/usr/lib/python2.6/site-packages/guestfs.py", line 681, in inspect_os
(nova.compute.disk): TRACE: return libguestfsmod.inspect_os (self._o)
(nova.compute.disk): TRACE: RuntimeError: aug_get: no matching node
(nova.compute.disk): TRACE:
2011-08-09 04:36:19,787 nova.virt.libvirt_conn: instance instance-00000015: ignoring error injecting data into image 40 (aug_get: no matching node)

nova.conf

--verbose=false
--ec2_url=http://192.168.3.192:8773/services/Cloud
--s3_host=192.168.3.192
--cc_host=192.168.3.192
--rabbit_host=192.168.3.192
--sql_connection=mysql://nova:nova@127.0.0.1/nova
--glance_api_servers=192.168.3.192:9292
--use_s3=true
--libvirt_type=kvm
--use_syslog=false
--node_availability_zone=nova
--logdir=/var/log/nova
--logging_context_format_string=%(asctime)s %(name)s: %(levelname)s [%(request_id)s %(user)s %(project)s] %(message)s
--logging_default_format_string=%(asctime)s %(name)s: %(message)s
--logging_debug_format_suffix=
--use_cow_images=true
--auth_driver=nova.auth.dbdriver.DbDriver
--network_manager=nova.network.manager.FlatManager
--fixed_range=192.168.3.0/24
--flat_injected=true
--scheduler_driver=nova.scheduler.zone.ZoneScheduler
--image_service=nova.image.glance.GlanceImageService
--use_ipv6=false
--ca_path=/var/lib/nova/CA
--keys_path=/var/lib/nova/keys
--images_path=/var/lib/nova/images
--buckets_path=/var/lib/nova/buckets
--instances_path=/var/lib/nova/instances
--networks_path=/var/lib/nova/networks
--dhcpbridge_flagfile=/etc/nova/nova.conf
--dhcpbridge=/usr/bin/nova-dhcpbridge
--injected_network_template=/usr/share/nova/interfaces/
--libvirt_xml_template=/usr/share/nova/libvirt.xml.template
--vpn_client_template=/usr/share/nova/client.ovpn.template
--credentials_template=/usr/share/nova/novarc.template
--state_path=/var/lib/nova
--lock_path=/var/lib/nova/tmp
--vnc_enabled=true
--vncproxy_url=http://127.0.0.1:6080
--vncserver_host=0.0.0.0
--vnc_token_ttl=300