When you say ip address in lan settings you make no sense to me.
You got the port number 3128, is it a proxy server. If so what is the ip of the proxy server. Enter those proxy details and port number in limewire. You can get the proxy details from Internet explorer-> tools-> options -> connection -> lan settings
For using orkut, enter the address
http://www.atunnel.com directly in your internet explorer, no need to fiddle around