[flommer]

Drivers for the digi hardware are part of the ProTools software package and are not installable/up-dateable independently.......

Unless you do not want to use ProTools at all but only want to use the digi hardware with other software. In this case you can uninstall PT and use the "Standalone Core Audio Driver" (which has a new version 8.something)

But you can not install both. If you try to install the standalone driver over a PT installation then, to quote DTS, "bad things will happen".

Not sure if Cubase will need the newer hardware drivers... It doesn't seem likely because as long as Core Audio can work with your hardware, then it is Cubase that must work with Core Audio... Maybe that is where the problem lies.

Have you tried launching the Core Audio Manager? That should be launched first and then try Cubase. (PT can not be running when the CAM is used) The CAM can be set to launch automatically whenever an app that will use it is launched, but maybe it is not receiving the "call" from Cubase?