I'm using Flash MX 2004 Educational, and am having problems using movie clips as symbols.
I'm trying to achieve an effect whereby I build a small animation in a .fla file of its own, then import this as a movie clip into another file. I would like the animation to play, using the timeline of the symbol instance, and then animate the movie clip itself (either scale it or move it around) by using tweens/effects in the timeline of the main movie file.
At the moment I can't get the the clip instance to play its animation. Here are the steps I'm taking, what have I missed?
1. Open new flash file, create small animation (done)
2. Open second flash file, leave blank and go back to the first one.
3. Select all frames in timeline, right click -> copy frames.
4. Go back to blank flash file.
5. Ctrl-F8 (Create new symbol) make type = movie clip.
6. Paste frames into time line.
7. Step out of the symbol into the main movie, still blank.
8. Open library, drag an instance of new symbol to stage. (The clip plays ok in the library preview window)
9. Add some more frames to the main movie so it plays longer than 1 frame.
10. Hit play - nothing happens. Should the movie clip play its animation or do I need to do something extra to make this happen?

Bah - never mind, I ended up getting rouglhy the same effect by doing it frame by frame. Wasn't too complex of a movie. For a bigger one that wouldn't have been an option.

I figured it out eventually - really silly problem. All I needed to do was to hit Ctrl-Enter to actually see the .swf instead of the .fla preview. It's really not a great preview, since in any one frame the corresponding frame in the .swf may look totally different, due to movie instances playing, and some other strange problems I encountered.
Neither of my flash books points this out when describing Movie clips as symbol instances.
Another preview problem - I had an ellipse shape with a motion tween on it so that it would start really small, then get larger and then shrink again over the course of several frames. I painted a few extra things onto the ellipse to give the impression of a shadow. In the .fla it looked fine, but in the swf the outline of the ellipse had changed into a pointy polygon. Probably because it was doing some sort of dynamic level of detail on the elliipse, so when it was small you didn't notice, but it didn't make the outline smoother when the shape was enlarged.

I'm not that impressed with the preview as you may gather.....