[libvirt] Unable to open virt-manager

Hi, I'm trying to work remotely on a server with F12, using vnc. When I start virt-manager, I do not get the authentication popup, and instead I get this message: Unable to open connection to hypervisor URI 'qemu:///system': authentication failed Traceback (most recent call last): File "/usr/share/virt-manager/virtManager/connection.py", line 872, in _try_open None], flags) File "/usr/lib64/python2.6/site-packages/libvirt.py", line 102, in openAuth if ret is None:raise libvirtError('virConnectOpenAuth() failed') libvirtError: authentication failed RPM versions: libvirt-0.7.1-15.fc12.x86_64 libvirt-client-0.7.1-15.fc12.x86_64 python-virtinst-0.500.1-2.fc12.noarch virt-viewer-0.2.0-1.fc12.x86_64 virt-manager-0.8.2-1.fc12.noarch virt-ctrl-1.0.1-4.fc12.x86_64 libvirt-python-0.7.1-15.fc12.x86_64 Any idea what causes the popup to fail ?