browes internet from different VLAN and subnet

Dears

In my network we have different VLANS with different subnets  each VLAN with one or more subnets  and I install ISA server on subnet A 10.1.9.0 which contain other servers like DHCP and Active directory and in ISA server we installed 2 NIC one internal interface with static IP address 10.1.9.6 from Subnet A and external interface connected with DSL modem also with static IP and gateway

Now all users in subnet A 10.1.9.0 can browse internet but other subnets can not access the internet and I add static routing in ISA server as

>     route p add 10.1.0.0 mask 255.255.0.0 10.1.9.6

because 10.1.0.0 with mask 255.255.0.0 contain all other subnets in my network ex: 10.1.46.0/24

but also it is not working at same time we got the following error in Event viewer
ISA Server detected routes through the network adapter Internal that do not correlate with the network to which this network adapter belongs. When networks are configured correctly, the IP address ranges included in each array-level network must include all IP addresses that are routable through its network adapters according to their routing tables. Otherwise valid packets may be dropped as spoofed. 


Any help please to fix this issue

Thanks