When you attach a virtual disk with snapshots to a VM, you have to use the latest snapshot file in the chain, otherwise you'll end up with old data and break the snapshot chain.
Please shut down the new VM immediately to avoid further changes to the virtual disk, and provide a list of files in the VM's folder (with full names, sizes and time stamps) to get an overview of what's present. Based on this information I'll let you know the next steps.
André