Anyone using Izotope Vocal Synth in C9.5.1?

I 'm having issues with vocal synth being very unresponsive in C.9.5.1. When interface is open is takes several seconds for it to react to changes on any of the controls or moving it on screen. Makes auditoning sounds impossible really. When I close the interface everything is fine but again I can’t change interface settings on the fly. Using internal intel HD3000 graphics. Other Izotope products work fine. Anyone else using this plug in successfully??

I don’t have the issues you do, but it is hugely CPU hungry…I’ve only been using it in C 9.5.1 so I don’t now if it’s been an existing issue before.

Thanks In_Stereo , I’ve tried on a blank project with one audio track and one clip and its the same result. Asio meter barely moves and system monitor all normal which is odd.