Siements 5890 router

Question

I have a siemens 5890 router that just replaced an Efficient 5820 router. The WAN port on the router comes up, but the LAN port cannot be pinged from HQ.

I have the internal firewall off. I can telnet into the router's wan ip and then ping the cisco switch. I can telnet into the cisco switch and ping the router's lan ip. From the router, I can also ping workstations on the lan.

Any ideas? In the Cisco world, we overload the Ethernet port and Nat outside on the WAN port and Nat inside on the Lan port.