Dual Ethernet adapters on Ubuntu 10.04 server
 

10.04 locks up when 2 adapters are listed in interfaces
example eth0 ip= 12.46.24.220 eth1 ip=10.168.1.111

Just a check question: Do you intend to use those IP nos within LAN or have you two WAN connections?

hardware
 

Computer has 2 ea hardware ports on motherboard
The primary network interface
Example:
auto eth0
iface eth0 inet static
address 12.46.24.220
netmask 255.255.255.0
network 12.46.24.0
broadcast 12.46.24.255
gateway 12.46.24.111

iface eth1 inet static
address 10.168.1.25
netmask 255.255.255.0
network 10.168.1.0
gateway 10.168.1.10