This problem isn't just on my CS-80 VST, it is on 4 other Arturia VSTs too (Jupiter 8, Analog Laboratory, ARP 2600 and Prophet V).
I am running Cubase v5 on a Windows 7-64 machine.
All my other VSTs work perfectly.
When I increase the volume knob, it stays loud for a little while (it varies between a fraction of a second and as few minutes) and then goes back to mimimum.
Can anyone help as this is a major problem!