On SLES11 SP1 Xen server I used LVM snapsots to backup VM's.
My script successfully did the following:
1. shutdown VM
2. run lvcreate to make a snapshot
3. start VM
4. backup the snapshot
5. run lvremove to remove the snapshot

After upgrade to SLES11 SP2 lvremove brings an error:
"Can't remove open logical volume..."

There is a workaround:

dmsetup remove <volume_group>-<snapshot_volume>
dmsetup remove <volume_group>-<snapshot_volume>-cow
lvremove <volume_group>/<snapshot_volume>

But I hope this workaround is only temporary till next patch for LVM