There are many services today which pipe radio through port 80. You need a product that will monitor traffice on the application layer in order to prevent such traffic. I am not aware of a way to do this in a PIX or a router but there are third par...
I have had this problem on V6 also. The only way I have been sucessfull is to use a cross over cable pulled directly into one of the ethernet ports on the pix and then use a define and ip for the pix with the tftp server being the next ip (i.e 192.1...
The problem is that you are trying to get the PIX to do routing of a packet in and out of the same interface. It can only route between interfaces. This is built into the PIX as a security rule. So you will need to make your 1600 the default route...