Adventures in Blu-ray; or, Is This Thing On?

I have a Sony BDP-S350, a hand-me-down (as most of my electronics and a fair amount of my media are). I should be able to plug it into a router or modem with an ethernet cable, thereby connecting it to the Internet so I can take part in "live" viewings and download firmware updates for the player. However, so far my attempts have only resulted in this error message: "Cannot communicate properly with DHCP server."

Does anyone know how I can fix this, preferably in time for the Sherlock Holmes "Live Community Screening Event" with Robert Downey, Jr., at 9 p.m. on April 1st?