The gnutella.net file is too small...the file should be around 25 KB (25000 bytes), yours is 0.3 KB.
Try replacing the file again. Just go through it really slowly & make sure that you've deleted the existing tiny file & replaced it with the larger one Double check that LW's properly closed by checking in Task Manager to see whether there's a LW process running, before you replace the gnutella.net file.

I'm not sure about the password problem with your router. I don't have a Linksys, but my router only needs a username & password to log into the router, not to save settings. When you set up port forwarding before, was it on the same Vista computer? Hopefully the Linksys site has some answers for you. Otherwise, try having a look on Google...maybe other people have had the same issue