filter-id help

I am running freeradius 1.0 . My server has been running for several years and has worked great authenticating users with a PIX and dialup servers. We are adding a watchguard firewall. Freeradius needs to send the watchguard the following filter-id on successful authentication: IPSEC_RADIUS. It appears to just send RADIUS and causes the authentication to fail. I know this is simple but I am having trouble getting this to work. Please help Dan