Windows 2003 Server SP2 WAN NIC stops passing DNS until reset

Problem: clients on LAN can not do DNS resolution several times a day. Bounce WAN NIC card on Windows 2003 server and clients can DNS resolve again.
Windows Server is doing DHCP, DNS, IP Routing, NAT/Firewall on server.
DNS and DHCP(DNS setting) are set to internal IP address of server, 192.168.0.1

WAN NIC is connected to QWEST DSL modem.

Clients can ping out to WAN using IP addresses but can not resolve Domain Names so NIC is not really down, just stops routing DNS.
DNS is set to have local LAN server be the DNS server but does have WAN FORWARDERS configured.

I am stumped. I think its something to do with the IP Routing, NAT or even something like ARP dynamic vs static, but can’t pin it down.

Thanks,
Steve