Your comments

So I noticed this stubbed CinemaCurveTrackControl.cs exists in the old version of CD, so we may have provoked this by installing the 1.0 version over top of the 

I will confirm this with Adam's build when he gets in on Monday, but at least we know what to look for if this pops up again. I really doubt Unity is generating stubs just to mess with us but stranger things have happened.

Thanks for your attention on this, and letting me talk it out here :)
Here's a warning we get when we load it up in our project -- 

Assets/ThirdParty/Cinema Suite/Cinema Director/System/Editor/Controls/TrackControls/ActorCurveTrackControl.cs(12,39): warning CS0436: The type `CinemaCurveTrackControl' conflicts with the imported type `CinemaCurveTrackControl'. Ignoring the imported type definition

I noticed that DirectorEditor.dll has a fully-fleshed out definition for CinemaCurveTrackControl, and for some reason we had a CinemaCurveTrackControl.cs file:

public class CinemaCurveTrackControl : TimelineTrackControl

Once I removed that source file, the Curves are editable once again!

So the question is how did this get generated? (that's a hypothetical question, I'll be trying to figure out why on our end here). Once Adam gets in on Monday I'll see if this file was generated on his machine as well. 

Thanks for looking into this Adrian. I can add timeline items from the actor track without issue, but the curve track has significant issues.

Adam has confirmed that it happens outside of perforce (i.e. on his local project which he was using for demoing purposes), after he reloaded Unity a couple of times. I'm going to try to do the same myself, I realize this isn't a lot to go on.

I've loaded up the "Director Basics" scene in our main (p4) project to provoke some errors, the first image is when I try to resize the Curve Clip on the Splash Camera Group:

And here's what happens when scrubbing across the same Curve Clip:

If I can get this issue to reproduce while using a local project I'll be sure to let you know how I did it.