Comment 8 for bug 671163

Could not reproduce on 10.04 (amd64) host either.

Please start up the VM with libvirt, and do 'ps -ef | grep kvm' to find the
command being used to start the VM. Then trim things like vnc, serial,
parallel and monitor options, add 'monitor stdio', and start the command
by hand. Try it once with no vnc option, and once with vnc :1 (and
subsequently connect with 'vncviewer :1' from a different terminal).

For instance, in my case the original command was

/usr/bin/kvm -S -M pc-0.12 -enable-kvm -m 1024 -smp 1 -name windows -uuid 376b7084-555c-d0b3-a1b9-ae165b56c4ca -chardev socket,id=monitor,path=/var/lib/libvirt/qemu/windows.monitor,server,nowait -monitor chardev:monitor -boot c -drive file=/mnt/srv/libvirt-storage-pool-1/win2003-r2-sp2-32.img,if=ide,index=0,boot=on,format=raw -drive if=ide,media=cdrom,index=2,format=raw -net nic,macaddr=52:54:00:33:ed:0b,vlan=0,name=nic.0 -net tap,fd=59,vlan=0,name=tap.0 -chardev pty,id=serial0 -serial chardev:serial0 -parallel none -usb -vnc 127.0.0.1:0 -vga cirrus

so I ran

/usr/bin/kvm -S -M pc-0.12 -enable-kvm -m 512 -smp 1 -name windows -boot c -drive file=/mnt/srv/libvirt-storage-pool-1/win2003-r2-sp2-32.img,if=ide,index=0,boot=on,format=raw -monitor stdio -vga cirrus