WINS on Samba server and Routing

hi, all. i've got a wierd problem with wins routing. my network has a
samba server that's also providing WINS services. it exists on a
172.16.0/24 subnet. any computer on that subnet can access the name
services and samba services just fine. however, any computer behind a
linux router on a 172.16.5/24 subnet can not access samba. those
computers can ping and get out to the internet and ping the samba
server. the wierder part is that the computers on the 172.16.5 subnet
register in the WINS database on the samba server, but do not get
replies for netbios name requests. There are no other Win2K or
samba/wins servers on the network, and each of the clients has the
proper IP address of teh samba server as its wins server. does anybody
have any suggestions as to what might be preventing samba response
through the linux router? I have tried both a freesco router and a
plain slackware installation with no IP Tables rules and the proper
routes set up. The Samba server can even ping the client!

additional info:

topology:

Samba Server (172.16.0.1/24) <--> (172.16.0.5/24) Linux Router
(172.16.5.1/24) <--> (172.16.5.2) Client

smb.conf:

[global]

workgroup = lbjhs
netbios name = fileserver
server string = LBJ Samba Server
hosts allow = 192.168.0. 127.0.0.1 172.16.0. 172.16.5.
security = user
ssl CA certDir = /etc/ssl/certs
socket options = TCP_NODELAY
interfaces = 172.16.0.2/24
local master = yes
os level = 64
domain master = yes
domain logons = yes
logon path = \\%N\%u\Profile
wins support = yes
wins proxy = yes
dns proxy = no
announce as = "NT Server"
browse list = yes

Linux Router routing table:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref
Use Iface
172.16.5.0 0.0.0.0 255.255.255.0 U 0 0
0 eth1
172.16.0.0 0.0.0.0 255.255.255.0 U 0 0
0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
0 lo
0.0.0.0 172.16.0.1 0.0.0.0 UG 1 0
0 eth0

Linux Router iptables:

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Thanks