I was going to begin using Melodyne when I notice the multidock is not responsive to any mouse inputs.
Keyboard shortcuts work, and the arrow keys will move the focus, but it not useable in this condition.
I can drag windows into the multidock, but not out.
I've tried blank projects, new projects, and old projects, all with the same results.
Any ideas?

I hate missing the obvious.  Installed Stardock Windowblinds on Windows 8.1.  In the past I have always excluded Sonar from being skinned.  I had forgotten about that.  Once I told Windowblinds not to skin Sonar, the Multidock worked again.