Drag and drop not working and video conflict in SL 3

Ok, this gets a bit complicated. First, let me say that everything works just fine as a Preview. But, depending on the Publish format, either .mp4 videos inserted into frames will not play, or matching drag and drop quiz frames default to being incorrect even when the answers are correct.

The videos are inserted into various frames. The user accesses each from one frame, called The Directory, that takes them to the frame where the video is inserted and the video starts automatically. After the video finished, the user clicks to return to the Directory.

The matching drag and drops may have the same number of drag objects as drop objects, say 4 and 4; or may have more drag objects than drop objects, say 6 and 4. I want the learner to have to choose which drag objects go to which drop objects. Consequently, in the Form view, some Drop Targets have targets, some have none.

When publishing in HTML5 only, to the Web, the video does not play, although the audio does. The drag and drop work perfectly, as well.

Publishing to HTML5/Flash, the same thing happens, audio but no video, and drag and drops work.

Publishing Flash/HTML5, the videos work, but the drag and drops all display as Incorrect.

Finally, publishing Flash only, The videos work, but the drag and drops do not.

I also notice that some of the drag objects on a frame snap to the drop objects, but some do not. Hmmmm.

And here is a kicker: I created a separate scene, totally unconnected to any other scenes or frames, copied and pasted The Directory, a frame with video, and a couple of drag and drop frames. I then published only that scene in HTML5 only, and everything works!?!?

What am I missing? Any ideas about this?