The update of Flash Player 20.0.0.267 caused horrible sound and instability problem in my app scaring users away.

On the update of Flash Player 20.0.0.267 in Chrome/Firefox/Adobe-Flash-Player, under specific environment which we have already applied in thousands of SWF files, we find it 1) unable to stop playing the sound which is placed on Timeline by ActionScript "this.stop" in our launched game, and 2) it could also cause multiple sound playing simultaneously resulting in loud noise and sudden crash on browser just within a few seconds. 

I have made a test to demonstrate the problem (but not limited to this case in reality):

1. In Adobe Flash Professional CS 5.5, start a new project by "New Project" with using "ActionScript 3";

2. In stage timeline, ensure we have extended to totally exactly 2 frames;

   Note: "2 frames" is a must.  The bug does not happen in "1 frame" or "3 frames"

3. In stage area, create a Symbol of Movie Clip, namely "Symbol 1";

4. In "Symbol 1", set 3 layers with timeline length around 30 frames;

5. In "Symbol 1", add a rectangle at key frame 1 in Layer 1, add an Action of command "this.stop();" at key frame 5 in Layer 2, and set the "Sound" Property at key frame 10 in Layer 3 using any MP3 file, Sync-mode to "Stream" and "Repeat", then close the "Symbol 1" movie clip;

6. Make sure that the "Symbol 1" is placed in Stage area, then save;

7. Publish to SWF file.

8. Open with the output file with Flash Player 20.0.0.267 in any platform.  The expected result would be a sound clip being played periodically, even though "this.stop();" has been run before it reaching the frame to play the sound.

Here is how we reproduced a more serious bug by inserting some irrelevant code with instruction in addition:

9. Close Flash Player opened in Step 8;

10. Continue to edit the same file in Step 1 in Flash Professional CS 5.5;

11. Add a new layer in Stage timeline;

12. Add an Action at frame 1 of the new layer with ActionScript "trace('abc');";

13. Publish to SWF file;

14. Open with the output file with Flash Player 20.0.0.267 in any platform.  The expected result would be A LOT OF sound clip played together causing loud noise.

Here are the links to the FLA and SWF we produced in the experiment above.

https://www.dropbox.com/s/u1rg04ocftn93ma/fp_bug_20.0.0.267_auto_sound.fla?dl=0

https://www.dropbox.com/s/7s3fdm1ifh3kqhh/fp_bug_20.0.0.267_auto_sound.swf?dl=0

https://www.dropbox.com/s/fj5kj5z46mx8wth/fp_bug_20.0.0.267_loud_noise.fla?dl=0

https://www.dropbox.com/s/qh5z7r13s487dkd/fp_bug_20.0.0.267_loud_noise.swf?dl=0

I suppose all computer with the Flash Player 20.0.0.267 should generate the same result.  We are still desperate to seek out any solution.