You said that you don't have Multiboot and that you formatted the USB stick. I don't quite follow becaue we use the USB stick only for Multiboot. I guess that the trouble could easily be a corrupted Flash Image. I would download the Image again (and not use one which you have on your PC) and Flash your box with the newly-downloaded Image using a Null Modem Cable and Dreamup. Then, after setting up the Flash Image with Channel Settings etc I would then use FWPRO to put the same Image on Multiboot on a USB Stick.
The USB stick provides more Memory space, hence a smoother working Image.
Unless it is some faulty component, by this method you should sort everything out, Audio problem included. And if you do sort things out, you may then paste that Line about the Audio which would put the English audio as default.
Wish you luck.