[Users] Can't add NFS domain

Hi, all, I've installed engine on FC17, no problem, and tried host/node iso image on ovirt.org, it can add as host in engine, but just can't add NFS domain with the host (engine web page showed no action after clicking "Add NFS Domain"). I've tried all the 4 iso node images on ovirt.org, no avail. I also tried to install a fresh FC17 as host, but I lack detailed instructions to install vdsm on it. Any help? John Xu