Content open/close trigger to play/stop media not working in html5

Hello,

I've read other posts about glitches relating to audio and html5 but I haven't found a solution to my problem...

Example 1

On a slide I have some text and button/marker which displays some additional info.

I have audio file 1 (audio version of the text) set to play automatically.

I have set up a trigger to pause audio file 1 and play audio file 2 (the additional info) when the the content opens (which is when the button/marker is clicked).

I have also set up a trigger to stop audio file 2 when the content closes so they don't play at the same time.

Example 2

I have a diagram (a marker interaction) with 4 markers. I've set each one to play a separate audio file when opened.

So I have:

Marker Shape 1

Play media Sound 1 When content open

Stop media Sound 1 When content closing

Marker Shape 2

Play media Sound 2 When content open

Stop media Sound 2 When content closing

Both these examples are perfect in the preview, in html and in flash but they don't work at all in html5. 

Any workarounds or solutions out there?

Thanks

Lee