It is my understanding that you can NOT use the PIX to route between two subnets connected on the same inside interface.
The PIX will not take receive packets and send them out the same interface that it receives them on.
In other words, the PIX will not route for you.
You will need a "router" to actually do this on the inside of the network prior to packets arriving at the inside interface of the PIX.
I believe that this has always been the case and, to date, remains unchanged.
Just looking for corooboration....thanks for any input