CZML playback in 1.4 bug?

We're using Cesium 1.1 because CZML playback was not working in 1.3, and now it looks like 1.4 has a problem. Do you guys want the CZML file I'm using?
It plays for a good amount of time then fails. I'm using the demo here http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/index.html

An error occurred while rendering. Rendering has stopped.
TypeError: Cannot set property 'id' of undefined
TypeError: Cannot set property 'id' of undefined
    at R.updateObject (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:397:24741)
    at L.update (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:397:25863)
    at g.update (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:400:11199)
    at http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:418:2241
    at i.raiseEvent (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:379:4941)
    at l.tick (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:382:641)
    at M.render (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:416:5162)
    at t (http://cesiumjs.org/Cesium/Build/Apps/CesiumViewer/CesiumViewerStartup.js:415:27788)

If you can post the file, that would be great.

Sorry, I cannot repeat the problem. I probably needed to F5 the app. The CZML playback looks good !