qmp command 'balloon' failed

Hi All,

im getting a weird error whenever i try to rollback to an snapshot on one of my KVM machines?

its coming up saying 'TASK ERROR: VM 162 qmp command 'balloon' failed - unable to connect to VM 162 socket - timeout after 31 retries'

but when i connect into the kvm machine, the machine has rolled back to that point in time?

any ideas?

Regards

Simon