Sonar X2 with 64 bit Auto-tune VST

I have a problem: Auto-tune plugin appears just in "grey window". If I load saved preset, some buttons may appear, but otherwise AT is graphically just grey window :/ AT works and appears normally in new small project, but I have tried it in some bigger projects - and just grey screen appears. I use lot of Waves plugins in those big projects. And there is about 5 Waves mono plugins in same track with AT. I think AT prosesses normally - so maybe this is just a graphical issue? I have latest ATI drivers and i7, 6 core processor 64 bit PC. Can anyone help? Thanks! :)