Keyframe Tray Below Timeline - Strange behavior

I love the addition of the keyframe window and the keyframe tray. However, after updating to b2 I've noticed that the keyframe tray below the timeline becomes inaccessible if you have stacked timelines enabled. The icon grays out unless I turned stacked timelines off.

To clarify: I don't actually have two timelines open, I just like to enable stacked timelines so I can easily switch between them using the tabs.

+ 1 You should be able to see where your keyframes are in context of the timeline when using stacked timelines.

This is not new to the 2nd Beta. It was true in the original as well.

The Keyframe Tray simply doesn't work with Stacked Timelines.