I'm wondering maybe if this doesn't have anything to do with the PIX configuration at all, but maybe rather my router. This is the double-Jeopardy bonus question...

Assuming my PIX passes along a packed from an untranslated IP on the A.B.C.192 subnet to the router, which has its interface on the A.B.C.128 subnet, will it know what to do with it? Does PIX in this instance perhaps do something to the request that makes it valid on the .128 subnet? If not, how does one get the router on the outside to field requests on the .192 subnet?

Food for thought. Maybe why this is why I have much better luck when configuring using NAT/PAT, because the request itself "becomes" a request from the PIX's outside interface on the .128 network, which the router can field from there.

FIIK.