Cannot ping 2nd NIC card on server from Client

I have a customer with a new Dell Poweredge Server 1300 with Windows 2000
I installed a 2nd 3com Nic for their IDSL Internet. I want to use NAT to share the Internet. I have configured DHCP with class C IP's. Server Internal IP 192.168.0.1 Sub 255.255.255.0 Client machines get 192.168.0.2-12 The 2nd server NIC has IP of 64.67.x.x sub 255.255.255.252 The server works fine with the Internal network and can browse the Internet. The problem is that the client manchines can ping the server's 192.168.0.1 address but cannot ping the 2nd card.........HELP!!!!!!!!!

NIC 1 IP 192.168.0.1
Sub 255.255.255.0
Gateway 64.67.x.x

NIC 2 IP 64.67.x.x
sub 255.255.255.252
Gateway = IDSL routers IP


note: the solution is not to use sygate or winproxy etc. because in order for all of these programs to work you must still be able to ping both cards

Sorry forgot to mention IP forewarding has been enabled

Sorry forgot to mention IP forwarding has been enabled

how bout setting the gateway of the client machines to the ip of the 1st nic of the server machine. ie. set the gateway on all the 192.168.0.2-12 machines to 192.168.0.1