Wireless router assigns IP but ping does not reach router

OK. I have tried the following combination. Connected the LAN port of the PC
with the LAN port (notice not WAN) of my wireless router (it has 4 LAN port
and 1 WAN port) using ethernet cable. Then I connected the LAN port of my
Laptop using ethernet cable to the LAN port of the wireless router. The WAN
port of the wireless router is set a fixed IP address 192.168.1.1 with
subnet mask 255.255.255.0. The WAN port is not connected to anything (since
I want to share my network between my pc and laptop and may be share dialup
connection of the pc). Both the LAN card of the PC and the Laptop is set to
get IP address automatically. The IP address of the wireless router is
192.168.0.1 and it is setup to act as a DHCP server. Everything works fine
upto this point. The PC is assigned the IP address 192.168.0.101 and the PC
is assigned the IP address 192.168.0.102. Both PC and Laptop can ping each
other, can ping the wireless router and use windows filesharing.
Now I removed the LAN card from the slot of Laptop and connected the
Wireless Lan card. The card works fine in my office. The wireless router is
setup with the same SSID as it is setup in the Wireless Lan card. WEP
security is disabled. Wireless Lan card is setup to get IP address
automatically. The Wireless Lan card gets IP address from the Wireless
router. The assinged IP is 192.168.0.100. The wireless Lan card shows
excellent radio connection. But I cannot ping the wireless router
(192.168.0.1) or the PC (192.168.0.101). The PC can ping the Wireless router
but cannot ping the Laptop.
Can someone please help?

Thanks

NM