Networking Tablet PC

I'm having a bit of a problem networking a new tablet pc. Yesterday I was able to configure Local Area Connection 1 with the proper static IP and gateway and DNS and all that jaz, and it worked just fine. However, today, the connection will not work. I can not access any computers on the network, and cannot get to the internet.
I tried some pinging, and can ping the tablet pc's ip as well as the loopback, but cannot ping any other computers on the network. Interestingly enough though, when I set the tablet's IP to an IP that was already in use, it popped up an error message warning me so. I'm not really sure where to go from here. It's not a wireless conflict, this tablet does not have wireless hardware. Any ideas would be awesome.

-Mike