In PIX A you will have to add a line in your nonat acl and crypto acl
permit ip 10.10.10.0 255.255.255.0 192.168.1.0 255.255.255.0
Same thing in PIX B
permit ip 192.168.1.0 255.255.255.0 10.10.10.0 255.255.255.0
and in PIX B you need to add a route for the 192.168.1.0 subnet.
route inside 192.168.1.0 255.255.255.0 10.10.11.x
where 10.10.11.x is the IP address of the router