libvirt users - Mar 2014 - Migration failure after libvirt upgradation

Team,

I'm trying to migrate a domain offline(shutdown mode) using  libvirt-python
API 'migrateToURI' but it gives me an error :

libvirt: QEMU Driver error : Requested operation is not valid: domain is
not running

When I tried the same API for live migration(running and suspend mode), it
gives me an error:

libvirt: QEMU Driver error : Unsafe migration: Migration may lead to data
corruption if disks use cache != none


Below are the versions of the virtualization softwares I am using currently
:

Hypervisor : KVM
qemu        : 1.0
qemu-kvm : 1.0
Libvirt        : 1.2.1


Earlier, I had performed offline and live migration *successfully* with
these versions:
Hypervisor  : KVM
qemu         : 1.0
qemu-kvm  : 1.0
libvirt          : 0.9.8

Also, I would like to know whether it's possible to migrate a domain having
snapshots?

Kindly guide me through this.

Thanks in advance

Regards,
Shweta