g4 powerbook wireless problem

I have a 15" G4 powerbook that is connected wirelessly to a D-Link router. It is set for 40/128 bit encryption. I enter the 10 digit Hex key (for 64 bit or 40 bit encryption) and it shows up as connected. In the system preferences, under networking I get an IP that is sequential from the router. So i have signal and an IP yet I can't connect to anything. I can't even ping other computers or ping the powerbook from other computers. I'm running OS X Panther with the default wireless card for the notebook. Even when encryption is turned off, same problem. Again, I receive an IP but no connection. Any help would be appreciated.