MaxterHost: Are you able to ping the ip from within the server or not? If you can't ping the IP from outside the server, try to redo the "ifdown eth0;ifup eth0" since the router might not have picked up the new IP address.
We always find a 'range' file is easier to deal with on Redhat based hosts.
How to bind a range of IP's on a Redhat/Linux System.
You will need to make changes to the ifcfg-eth-range0 file. Adjust the start and end points of the range in the file to use the first IP address after your base IP (the one that is already bound and working) and then modify the 'end' to be the last usable IP on your range.
% vi /etc/sysconfig/network-scripts/ifcfg-eth0-range0
If there is 2 ranges on the host, the second range would use a 'ifcfg-eth0-range1' file and CLONE_NUM=5 which would start at the next available interfacec number after the last used in the range0 file.
The IP range option only works when you have a consecutive list of IP addresses as shown by LTADMIN. Aka xxx.xxx.1.1 thru xxx.xxx.1.20. The two IP's your're working with sit on two separate class C's, so that wouldn't work.
Have you tried contacting Plesk support? I'm thinking you might get faster and better reponse going through them since they would have direct access to your server whereas all of us here in WHT are shooting blindly into the dark.
Doh!. I misread and thought he was trying to bind all of the IP's assigned to his VLAN. May want to check and see if the secondary IP is part of a range routed to your host and you can create a second range file for that block and use it along with a first range file for your base IP range.
If not do as the others said and bind them by hand or using modified ifcfg-ethX files.