Deep Freeze and Sophos

Anyone got any tips regarding Deep Freeze and Sophos?

We have just got the fancy enterprise console version going, trouble is a lot of the classrooms are locked down using Deep Freeze so any updates / client push outs get undone on reboot/shutdown!

Ideally we could install Sophos on a 'thawed' partition but do some of the updates affect the registry?

You have to set a maintenance schedule from the console....and time Sophos/windows updates etc to coincide with the 'thawed' machines.