[xubuntu] KVM or bridged network causing kernel panic on 13.04?

Hi,

I have an Xubuntu host running 13.04 with qemu-kvm and bridged networking per the documentation. The guests are on LVM2 and generally using raw disk type.

I get occasional kernel panics, like once a week. So far I've been so anxious to get the box back up that I haven't had time to really investigate, but on one occasion the screen showed an exception which was in the br0 interface.

So I guess I have to ask a couple questions:

1. Is anyone else getting this sort of thing? I think not because I'm not finding it in the forum.
2. Is 12.04 going to be more stable than 13.04?
3. Is it feasible to wipe off the 13.04 on the host and put 12.04 on it, and still use the same guests?
4. Is it reasonable to expect more stability that way?

Thanks.