Thanks for the quick response. I'm connected to my work's LAN using a Reaktek RTL8139/810x ethernet adapter. I have no idea how the network is connected to the Internet.

I'm already running Java 1.4.2. and just installed the JRE 5.0 Update 1 that you linked me to. Still no dice.

This is strange because I was connected just last night and have made no software or hardware changes to my laptop since then. Could be a network problem?