static routing not work

Static route to a second external network is set but not work.

System in this external network are reatchable from firewall (ping), but clients cannot reatch it.

tcpdump show no outgoing package with right interface.

Route lookup on Webadmin show: "Can't find route for..."

On console the route is shown correctly.

Firewall rule are exist and will used with allowed, no filtering is active!

Outgoing traffic will masq. behind outgoing interface.

Dest port is 8080. Web proxy port on firewall is 3128.