Cannot ping router or connect to internet, but I can access its web config page

I am connected directly to a WRT54G Linksys router that has worked fine for months. If I go to its diag screen, I can ping/traceroute any internet site. The fact that I can interact with the router via a browser should be cool, but its not. ;-) I cannot ping the router from my connected machine (the one talking to it via browser), and I cannot access the internet from my machine. My wife recently moved the router to paint. Other then that, its been great since June. I've rebooted everything. I've called Time Warner Cable (they can see my cable modem and my router). How can my machine get an address via DHCP, but act like it cannot see the router? How can I talk to the router via port 80, and have a router that can see the net, but I cannot see the net? I'm stumped. And bummed. Ideas welcome.

In case you are going to ask:

yes, the router gets an address from the cable modem
yes, all machines get addresses from the router

Thanks,
Corey