Did you try changing port numbers? Your port test failed, so something's 'blocking' LW's default port. In LW tools > options > advanced > firewall > change LW's listening port to 65000 > apply > ok.

Windows Live OneCare comes with a firewall. So does XP.
You need to make sure that there's only one software firewall running on your computer.... so you need to turn off either XP's firewall or WLOC firewall

To check which firewall's turned on control panel > security centre. You'll see the firewall status (on or off). To check which firewall's turned on, click on the little arrows pointing down, beside the firewall.

To turn off the XP firewall go to control panel > windows firewall > click on the 'off' button > ok.

I don't use WLOC but I found this info about turning off the firewall: How do I disable the Windows OneCare firewall? :: Free Tech Support from Ask Dave Taylor!

Your Motorola has it's own firewall. You don't have to turn that off, but you might need to try port forwarding, if using UPnP isn't reliable. First thing you need to do is to set up a static IP address. See here: PortForward.com - Free Help Setting up Your Router or Firewall

Once you have the static IP address set up, then you can port forward. See here: Port Forwarding for the Motorola SBG 900

Remember... LW's listening port, port in LW's 'manual port forward' box & port forwarded within your router setup must all be the same number