I've got an SBS server with 2 NICs running ISA 2004. I can connect to remote shares via IP from workstations behind the ISA server just fine (e.g. \\xxx.xxx.xxx.xxx\c$ where xxx.xxx.xxx.xxx is an IP on a remote network).
I cannot connect to remote shares from the SBS machine itself. Looking at the ISA logs I'm getting:
FWX_E_OUTBOUND_PATH_THROUGH_DROPPED 0xC0040030 A packet generated on the local host was rejected because its source IP address is assigned to one network adapter and its destination IP address is reachable through another network adapter.
The ISA log for the above error message show my source IP as the one assigned to the internal NIC, and the destination port of TCP 139.
I can telnet to the destination on port 139 and it connects, but I'm seeing that the source IP in this case is the one assigned to my external NIC.