What version of Java are you using? Try updating to Java 6. Use the JRE offline installer & remove any old Java versions before installing the new one.
http://java.sun.com/javase/downloads/index.jsp

In LW file > disconnect. Let it sit for 5 mins, now file > connect.

How do you have the Linksys set up (UPnP enabled, port forwarded or neither)?

I wouldn't advise you to run without a firewall, rather configure the firewall to allow LW.