What I would do is comment the whole line and type in your gateway directly.
# This sets up the Default Route
#
#GW=`ifconfig $Wan | grep "inet addr:"| grep -v "127.0.0.1" | cut -d: -f2 | awk '{ print $1}' | cut -d. -f1,2,3`
GW="192.168.0.1"
If this does not work then you have other problems.
Also can you post your interfaces and corresponding IPs. That way, it will be easier to track down where the connection is failing.