Routing Problem Win7 and XP

I am connecting several Windows 7 laptops via wireless to a wired network of XP machines. After several frustrating days trying to figure out why I couldn't see shares on the network I think I've finally caught the culprit: the netbios master browser. Can anyone shed some insight into what's going on below.

The wired network is a group of XP machines attached to a NAT router which provides DHCP addresses to the network. They are part of a workgroup and so there is no Domain Name Server attached. So long as this was just an XP network everthing worked fine, but it all went south when trying to attach the Windows 7 laptops.

I read that I would need to install the LLTD Responder onto the XP machines so I downloaded it from Microsoft and performed the installation which seemed to go smoothly. Except that it didn't seem to help anything get discovered. Then I read that I'd have to enable NetBios on all of the machines (not the Default option on the Wins tab, but the actual Enable option just to be sure). Still no connections. I checked system services: Computer Browser is running and so is TCPIP NetBios Helper. I made sure that Network Discovery is on under the advanced sharing tab on the Win7 machines. I switched off the firewalls. Still no connections. I can ping all of the devices on the network, and I can even do so using host names, which seems to suggest that name resolution is working.

The Win7 system event log provides what may be a big clue to the problem: NetBT throws EventID 4321: The name "WORKGROUP :1d" could not be registered on the interface with IP address 192.168.0.104. The computer with the IP address 192.168.0.100 did not allow the name to be claimed by this computer.

I ran NBTSTAT -A 192.168.0.100 to read the routing table and discovered what looks like the source of the problem:

Wireless Network Connection:
Node IpAddress: [192.168.0.104] Scope Id: []

BB1 <00> UNIQUE Registered
WORKGROUP <00> GROUP Registered
BB1 <20> UNIQUE Registered
SNTL_BB1 <20> UNIQUE Registered
WORKGROUP <1E> GROUP Registered
WORKGROUP <1D> UNIQUE Registered
..__MSBROWSE__.<01> GROUP Registered

This is an XP computer, which is acting as the master browser, and it already has an entry for the workgroup name and a unique entry also that would seem to be preventing the Win7 machines from connecting. Am I reading this correctly?
What might be the cause of this, and how can I fix it? I suspect that something is messed up with NetBios and which device is controlling access to resources on the network. I also suspect that I may not be going about this the right way and that I possibly shouldn't be using NetBios at all.

Can somebody see what's going on and suggest a way out? Thanks.

Petre.

Hello phuile,
The LLTD responder is only so that your XP machines will show up on the Windows 7 network map. If you can't get your Windows 7 machines to connect to the router wirelessly then your router is probably in need of a firmware update. What kind of router are you using for this?

Firmware upgrade to the routers did the trick. Win 7 and XP are now networking happily and so far seem to
be reliable. (I hope I'm speaking too soon!) Thanks for the suggestion.

Sounds good phuile, firmware updates have saved the day many times here. Glad to see that it worked for you. :)