Can't connect to internet

[LANS]

Software
XBian version: Tried with both 1.0 RC2 and 1.0 Beta 2
XBMC version: Whatever came with the installer from http://www.xbian.org/download/
Overclock settings: Whatever's default, I haven't overclocked it

Hardware
Power supply rating: 1.2A
RPi model (model A/B 256mb/512mb): B 512mb
SD card size and make/type:2gb Not sure manufacturer/type, it came with a camera and just says Kodak.
Network (wireless or LAN): LAN
Connected devices (TV, USB, network storage, etc.): TV, keyboard, mouse, LAN


I installed Xbian using the installer on the http://www.xbian.org/getting-started/ page. It loads and seems to work just fine on my rasberry pi. However, I can't connect to my network through it.

The ethernet lights on the board light up when its plugged in, and I know the connection is fine as I'm using it right now (with my laptop) to write this post. Also all of the lights on the board are on solid.

As far as network details, the router is a Buffalo WZR-600DHP running DD-WRT, into a 24-port unmanaged switch, which is then wired through the house. Other than Xbian, I haven't had any problems with this setup.

Any suggestions would be appreciated. Thanks.