WiFi ICS complex problem

[rdskl]

I have a small Home network using a WiFi router and am having problems sharing internet through PC2 to my XBOX.
Here is my Network toplogy:

visual:
http://www.geocities.com/rdskl/SETUP-3.jpg

Description:

PC 1 (1 Nic):

Connected to the internet via router using DHCP, given IP by router 192.168.0.100
Default gateway : 192.168.0.1
Subnet: 255.255.255.0

PC 2 (2 Nic):

Nic 1 : Connected to the internet via router using DHCP, given IP by router 192.168.0.101
Default gateway : 192.168.0.1
Subnet: 255.255.255.0

Nic 2 : Connected to XBOX via crossover cable, CAN FTP files. Static IP: 192.168.1.112
Default gateway: 192.168.1.1
Subnet: 255.255.255.0

XBOX (1 nic):
Connected to PC2's NIC2 via crossover cable. FTP works. Static IP:192.168.1.111
Default Gateway: 192.168.1.112
Subnet: 255.255.255.0

Now when I try to enable ICS on NIC1 on PC2 I get the error that 192.168.0.1 is needed to enable sharing. But I cannot change PC1's default gateway IP(its already set to DHCP).

I need to enable ICS on PC2 so the XBOX can access the net.

Pls help.

Thank you