Short version - On an adjustment layer, why is a keyframed Gaussian Blur effect disabled when a Noise effect is added?
Long version - I have two 5 second clips. I place both of them on the timeline so that one plays right after the other. I place an adjustment layer above, extended to cover both, so it's 10 seconds. I add the Gaussian Blur effect on the adjustment layer. I keyframe the Blurriness level to be 0.0 at 4 seconds and 30.0 at 7 seconds. I hit play and it works fine. I add the Noise effect next and set Amount of Noise to 5.0%. I play the video and notice that only the noise effect works, but in the time between 4 and 7 seconds when it's supposed to become blurry stops working. The blur is only influenced by the Blurriness amount set for the first keyframe (at 4 seconds), however, it is applied to the entire 10 seconds, and not just after 4 seconds. The second keyframe seems to become disabled when the noise effect is on. The order stack of the effects has no effect. Going to Sequence and hitting "Render effects In to Out" has no effect.. Enabling or disabling "Composite in linear colour" in the Sequence Settings has no effect.
Adding the Noise effect on a separate adjustment layer is the only solution I've found, but I really wish to know why both can't work together on one adjustment layer.