I have ISPConfig 3.0.5.4p6 running on Debian Wheezy and it runs great! I recently installed OpenVZ and I am able to create VM's manually and they show in the "vzlist -a" command, but when I create a VM in ISPConfig it doesnt work. I added a symbolic link with "ln -s /var/lib/vz /vz" and it still dont work. I followed these instructions https://www.howtoforge.com/installing-openvz-plus-management-of-vms-through-ispconfig-3-debian-6.0