I have finally figured out my iOS streaming without sound problem.
Basically when I set it as auto bitrate or I chose the lowest which is 384kb there is no sound, however if I choose manual 385kb I have sound.
Don't quite know why that is.
Now I have a problem where the stream stops after about 30 seconds, maybe bandwidth related as I only have about 400kbps upload on my dsl.
We really need an option for a 200kbps stream, as I will quite happily watch at that quality