Help with samba and multiple subnets

I have two subnets in may LAN 192.168.0.0/24 and 192.168.1.0/24. Both
subnets go out to the Internet through a Linux box acting as a
gateway, so the gateway has one interface in each subnet (192.168.1.1
and 192.168.0.1). In both subnets I have Windows and Linux machines
and I want to configure SMB networking using a workgroup (not a
domain), so one workgroup for more than one subnet.

I know that to enable SMB networking in multiple IP subnets I need a
domain master browser and one local master browser per each subnet, or
I need to use the "remote browse sync" to make the local master
browsers in each subnet talk each other. My problem is that the only
machine that has a fixed IP in both subnets is the Linux gateway. To
use this "remote browse sync" would I need two instances of samba one
running in each interface ? By now I just have one instance of samba
listening in both interfaces in the gateway machine, in the gateway
machine there is also a WINS server.

I have this Linux gateway configured to be the domain master and the
local master browser, but I am bit confused about if this machine is
the local master browser in both subnets or not.

Basically my configuration in the gateway is the following:
-----------------------------------------------------
hosts allow=127. 192.168.0. 192.168.1.
....
socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
....
interfaces=192.168.0.1/24 192.168.1.1/24 127.0.0.1/8
bind interfaces only=yes
....
#To be the DMB
domain master = yes
local master = yes
os level = 255
preferred master = yes
....
#To be the WINS server
name resolve order = wins lmhosts bcast
wins support = yes
dns proxy = no
------------------------------------------

It's quite weird because if I check the /var/cache/samba/browse.dat
file in the gateway I see that the machines in both subnets are there
and in the wins.dat file the ip of the machine is there. But then when
I try to browse the workgroup form a windows machine I get the famous
"Error 53" and I can not browse the workgroup.

Thanks !