My video camera has 5.1 channel surround sound so I was hoping to utilise this when producing my project. When I produce the file as a mpeg 4 the dolby 5.1 surround sound is greyed out, however it is availiable as an option when I produce the file as an mpeg 2.

I was under the impression that an mpeg 4 was better and is used as a standard when movies are put onto dvds. Why won't it allow me to produce my project with surround sound as an mpeg4? Any advice or information would be greatly appreciated.

Cheers