Can a nic conflict with networked machine?

[Rookie]

Hello, I just tried to install a second nic and got an error msg saying something to the effect of a conflict with ip address xxxxxxxx
which is the ip address of a machine on my home lan.

Is that possible? or is it motherboard chipset scrambling the I/O addresses? (these are socket 7 via chipset mobos on this lan)

If it is possible, then that means there is a relationship between the I/O addresses of the whole lan?

I'm gonna put in a different nic but I wanted to know if this I/O stuff is something to worry about in a networking environment

[psyklone]

well yeah, it sounds like you've manually set the IP addresses on the cards and two machines on the network have the same IP address, that's where you're getting the conflict.