The search function doesn't seem to know of the existence of any threads after May 2011 for me. 

So, R-Mix. 

What am I doing wrong.

I insert it on an audio track, the GUI opens but the central area where all the good stuff happens is just a blank white screen.

All the other controls are present & work (Effect / Noise cancel / Shape  / Inside Level / Outside Level

Any clues?

It works as expected on my non-Daw pc.

Seems like either a graphics issue or a corrupt install

I haven't experienced that, but maybe you can check this out: http://forum.cakewalk.com/fb.ashx?m=2670801

Regards,
Don

This has happened to a lot of people including myself. Restarting sonar usually solves it. If you have audio dropout, increase the midi buffer size in preferences 

Bibs

Yep, restarting solves it.

Thanks