I can reproduce this (at least the "unknown savevm section or instance 'hpet' 0" just doing:
qemu-img create -f qcow2 /mnt/x.qcow2 1G kvm -hda /mnt/x.qcow2 -vnc :1 -monitor stdio savevm /mnt/x.out
on the oneiric host, and then on precise host
kvm -hda /mnt/x.qcow2 -vnc :1 -monitor stdio -S loadvm /mnt/x.out
I can reproduce this (at least the "unknown savevm section or instance 'hpet' 0" just doing:
qemu-img create -f qcow2 /mnt/x.qcow2 1G
kvm -hda /mnt/x.qcow2 -vnc :1 -monitor stdio
savevm /mnt/x.out
on the oneiric host, and then on precise host
kvm -hda /mnt/x.qcow2 -vnc :1 -monitor stdio -S
loadvm /mnt/x.out