How to share my server's 2nd IP with more than 2 domains?

Hi everybody,

I have a problem using Virtualmin, i share the original IP with lot of domain, but i want to share another IP with an other lot of domaine (sorry for my english).

I've make a new server (with virtualmin) with my 2nd IP, all it's ok. (87.98.xxx.xxx (Private to this server))

But when i want to make a sub server or an other server using this new IP, i use :

Network Interface : 0 Shared on 91.121.XXX.XXX (1st IP) X Virtual Interface With IP (input text) 87.98.XXX.XXX (2nd IP) |x| Already active

i've checked the 2nd purpose and put my 2nd IP in thefield (checkbox already active checked)

But when i try to validate (with or without checkbox already active), Virtualmin says :

ERROR Failed to create virtual server : The IP address is already used by virtual server xxxxx.com

I check m interface on Webmin and we have eth0 = 1st IP eth0:1 = 2nd IP

Any idea to solve my problem?

Thanks to all