Rear Speakers not working in Vista 32-bit (Cambridge SoundWorks FPS1600)

[Zlash]

Hey!
I have a FourPointSurround Speaker set, Cambridge SoundWorks FPS1600, and the rear speakers don't seem to work properly. When I test the speakers they seem alright, with sound coming out of all the speakers, but the rear speakers don't make any sound when e.g. playing music.

I have looked around and have seen other people with similar problems, but unfortunately I haven't been able to fix this so know I decided to just make a new thread.

I am using Windows Vista 32-bit and my soundcard is Realtek High Definition Audio (or something, I think)

(And yes, I have setted the settings on "5.1 surround" and not "Stereo")