I'm assuming from your config that you mean 192.168.10.x cannot ping 192.168.1.x. Looking at your config, I notice a couple of things:
1. 192.168.1.1 is the inside addr of your PIX, so must presumably be on the outside of your router.
2. You have no route for the 192.168.10.0/24 network defined on the PIX.
3. Since both networks are on the inside of your PIX, the ACLs on the PIX shouldn't have any effect other than for traffic to the PIX itself.
I would add a route for the 192.168.10.0/24 net pointing at your 1600 and see if that rectifies your problem. If not, check that there are no ACLs on your router and check the logs on both devices.
HTH.