Making IPV6 routes Persistent in RedHat

Hi All, I'm having trouble getting RHEL to re-instate persistent IPV6 routes on reboot. I have the routes set up in /etc/sysconfig/network-scripts/route6-eth0 but they aren't getting applied on startup. But when I do an ifdown followed by an ifup, or a 'service network restart' I get the following message: RTNETLINK answers: No route to host ..Which is fair enough, as it seems that the IPV6 network isn't actually ready when the route is added. Has anybody got this working before? Is there somewhere else I should be adding the routes? Cheers, Leigh.