Settings for network

I have 2 laptops A & B
A connects to the internet via Wireless and is set with Internet Connection Sharing. It works.
Laptop B is connected to A via crossover cable and the network is fine at transferring files both ways.
I cannot get internet on B
I presume the network is accepted by firewall otherwise why share files.
I placed firewall on Interractive yesterday, still didn't work.
I unplugged network cable, replugged and hey presto internet on B after a request was triggered by firewall.
Start computers today, network ok, internet on A ok but no internet on B
Firewall on both. Disabling filtering either or both does not solve it.
[EDIT] wrong-turning of firewall B does solve it, turning on again stops it.

I cannot see what I am missing. I have tried automatic mode also.
Any help please?

[EDIT] If google is searched with firewall on and it doesn't work, turning off filtering still doesn't let it work unless Firefox is stopped then restarted and google searched again then it works until filtering turned on again.
Why does Firefox have to be restarted to get it to work when filtering turned off during a search?

 

The figures I have are...
laptop A
Ethernet 192.168.0.1
Wireless/Ethernet 192.168.1.64

laptop B
Ethernet 192.168.0.42
Gateway 192.168.0.1

Can you please tell me where exactly these should appear in the firewall settings to get through both firewalls?