hello,I have 2 problems:-please answer them one by one

[1]-i have ubuntu-8.04 and two nic-interfaces card(namely eth0 and eth1).on eth1 interface i have given ipv4 address 192.168.1.2 and nothing else.and for another interface eth0 i have left it for dhcp(for my internet connection) , if i run ifconfig command then i am getting 3 addreses on my eth1 interface they are-inet addr:192.168.1.2
inet6 addr: 2000:ffff::215:17ff:fe65:c1a9/64 Scope:Global
and inet6 addr: fe80::215:17ff:fe65:c1a9/64 Scope:Link
I dont know why i am getting two extra address. I think long back ago i was getting only one extra inet6 address(i.e. inet6 addr: fe80::215:17ff:fe65:c1a9/64 Scope:Link) and at that time i was not getting any global address So PLEASE tell me why am i getting these and how to remove these so that i can have only one address 192.168.1.2 (after my assigning).NOTE: My /etc/network/interfaces file has this info:
auto lo
iface lo inet loopback

iface eth1 inet static
address 192.168.1.2
netmask 255.255.255.0
auto eth1

iface eth0 inet dhcp
auto eth0

PROBLEM-[2]: I have another system having the same operating system as ubuntu-8.04.this time also i have two interfaces eth0 and eth1.on eth1 im using dhcp for my internet connection.on eth0 i have assigned ipv6 address 2001:468::3/64 Scope global.On this system also i am getting two extra addressess which i never assigned to my eth0.they are:
inet6 addr: 2001:468::219:d1ff:fe1e:e0cc/64 Scope: global
inet6 addr: fe80::219:d1ff:fe1e:e0cc/64 Scope: Link
Here also i think, earliar i was getting only one extra addr and that was link local addr(starting from fe80).
After ifconfig command I want only one global addr(2001:468::3 which i have assigned).PLEASE solve this problem also for me
here my /etc/network/interfaces contents is:
auto lo
iface lo inet loopback

iface eth0 inet6 static
address 2001:468::3
netmask 64
auto eth0

iface eth1 inet dhcp
auto eth1

If you do not need IPv6 ... then disable it.
Most networks do not use/need IPv6.
Most likely you have a kernel module running called ipv6 ... black list it.

Otherwise just ignore it.

No, i can't blacklist my ipv6 because im working on ipv4 to ipv6 migration and vice-versa.So, i should have my ipv6 up. but the problem is "why additional global ipv6 address is coming,which has not been assigned by me?and how to remove this addtional global address?"

I have tried this to remove but it din't work-
# ifconfig eth1 del 2000:ffff::215:17ff:fe65:c1a9/64
i did it on my first comp. which should have only ipv4 address-192.168.1.2. You are saying that i have to black-list the ipv6 address from here,so how to do it?

on my 2nd comp. i tried this-
# ifconfig eth0 del 2001:468::219:d1ff:fe1e:e0cc/64
to remove my additional global ipv6 address.her i need only 2001:468::3 (global address which i have assigned) so here i can't black list my ipv6 completely.

Please understand my problems and reply soon.Thanks alot....