Hi Iain,
Sorry to hear you're experiencing this - we've been looking into this, as some of us here have this, but some do not. We've been trying to isolate what makes the difference, so far it does not look like CPU, Win version, driver version, or GPU (so far).
Can I ask a question, do you happen to have Corona for C4D installed on those machines, or some other version of Corona (archicad for example), as well as the 3ds Max version?
(Internal ID=541445437)