Documentation of uname says it should be the nodename, and this is the usual behavior. You get FQDN through hostname -f and that looks it up through /etc/hosts (something like getent host `uname -n` | awk '{print $2}' :) So having just the nodename in /etc/hostname and the FQDN in /etc/hosts in between the IP address and the nodename is just fine.
I though do remember that there might be some weirdnesses with virtual servers and that these tools are specificly picky in that area, and I think openvz is one such case here. I could be wrong on that part though and hope someone could followup to that part.