Weird knob-snapping with some NI plugs

I got no response from NI Support, so I’ll see if someone here may have input.

Cubase 7.5.2, Win 7 64.
A few plugins from NI are exhibiting weird knob-snapping behavior, namely if I click on the knob and move the mouse to dial, the knob snaps to max/100%/fully-clockwise and can’t be pulled back down. I also tried alt-click, but that simply made the mouse cursor completely vanish.

All other plugins from other vendors are behaving normally, and even a few NI plugs (.e.g Solid Mix series) are fine. The ones exhibiting the problem include Transient Master, Supercharger, Varicomp, VC 76, Passive EQ.

Any ideas?