[CentOS] unable to assign static IPv6

I'm having a problem permanently assigning a static IPv6 address to my CentOS v5.5 box. I have IPv6 enabled and the link local address is automatically brought up. I can manually ifconfig the address but when I configure it in ifcfg-eth0 and restart the network init script the IPv6 address is not assigned.

Anyone have any ideas on how to fix this?

/etc/sysconfig/network-scripts/ifcfg-eth0: IPV6INT=yes IPV6ADDR=fdca:fefe:dace:07b1:0000:0002:B339:2817

$ cat /etc/sysconfig//network NETWORKING=yes NETWORKING_IPV6=yes

$ lsb_release -a LSB Version: :core-3.1-ia32:core-3.1-noarch:graphics-3.1-ia32:graphics-3.1- noarch Distributor ID: CentOS Description: CentOS release 5.5 (Final) Release: 5.5 Codename: Final