I Can't Use Netfornt Or Email Options

[wowdar]

I have in my PC a router with ADSL connection.
I done all configuration for USB -TCP/ic connection.

In my PC I typed in console:
ifconfig usb0 192.168.129.200 netmask 255.255.255.0
route add -host 192.168.129.201 usb0
iptables -t nat -F
iptables -t nat -A POSTROUTING -o eth0 -J MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/conf/usb0/proxy_arp
echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp

In the zaurus I typed in console:
route add default gw 192.168.129.200

I modified my /etc/resolv.conf in the zaurus with my DNS

Now in the zaurus if I ping
ping -c 3 66.102.9.104

is al ok and if ping
ping -c 3 www.google.it

is all ok
Now if I try to navigate with NetFront I recieve theese windows:
"No connection to the network. Connection now?"
I push yes and other windows say:
"Cannot find the device card for connection"
And now I can't navigate. I have the same wit mail.
How can I do?
Tanks Dario

[wowdar]

Model Zaurus SL C 1000
Rom Sharp Version 1.01JP
Kernel Linux 2.4.20
QTopia 1.5.4