Aaaaahhhhhh ...

I got it working ... it was just my stupid mistake.

Code:
while(media_playing(mHandle) > 0)



is totally wrong ... it must be

Code:
while(media_playing(mHandle) != 0)



what a stupid mistake ...

In all cases where I got the strange behaviour, media_playing returned a value < 0 ... that's all .... grrrrrr ....

Sorry for wasting your time.

Regards,
Pegamode.