Turning off firewall in WinPE 2005

[Stu]

I have made a bootable WinPE CD image which includes network drivers
for my NIC
I have turned on verbose logging (loglevel=2 in winbom.ini), and also
disabled the firewall (WinPEFirewall=Off in the [WinPE.Net] section in
winbom.ini), and get the following in the winbom.log file:

Starting Factory state "WinPE Firewall".
ERROR: An error prevented factory from disabling the firewall.
ERROR: Factory state "WinPE Firewall" failed.
Factory state "WinPE Firewall" took 0.406 seconds to complete.
Starting Factory state "Starting networking".
Factory state "Starting networking" finished successfully.
Factory state "Starting networking" took 15.860 seconds to complete.

The IP address I get assigned is 169.254.90.43, with autoconfiguration
enabled, even though the same NIC and PC gets a perfectly good IP
address from my DHCP server when it PXE boots.

I suspect that the firewall is still on, even though the image I
created (using an XPsp2 CD) with mkimg included the /nowf switch, and I
am trying to disable it in winbom.ini.

The network seems to be configured OK; the output from netcfg -v -s n
is as follows:

X:\I386\SYSTEM32>netcfg -v -s n

Network Adapters
-----------------

pci\ven_10b7&dev_9200&subsys_100010b7 3Com EtherLink XL 10/100 PCI For
Complete
PC Management NIC (3C905C-TX)


Network Protocols
-----------------

ms_netbt_smb Message-oriented TCP/IP Protocol (SMB
session)

ms_netbt WINS Client(TCP/IP) Protocol

ms_tcpip Internet Protocol (TCP/IP)


Network Services
-----------------

ms_netbios NetBIOS Interface

ms_rsvp QoS RSVP


Network Clients
-----------------

ms_msclient Client for Microsoft Networks

Does anyone know how I get an IP address from my DHCP server in order
to map network drives and access network resources from WInPE?
Is there a simple test to confirm whether the firewall is blocking
traffic?

Thanks in advance