NT User Logon across 2 Subnets

I have a routable subnet behind a Cisco 2620, (mask 255.255.255.0) this subnet contains the PDC/BDC/WINS/Exchange 5.5 and about 40 nodes. I also have another Cisco 2611 which has a routable external interface and an internal interface peforming NAT with a subnet 192.168.1.0 255.255.252.0 where most of the “normal” low overhead users reside. This subnet has no BDC or Domain but does have a WINS server. All the users are connected via HP Procurve 4000 switches which are (unfortunately) daisy chained. The only way it seems users can logon to the Domain (PDC) is with NETBEUI loaded on each client. I tried to configure the Cisco 2611 to pass UDP traffic, but it does not seem to help.