No Centre Audio From SB Audigy & Inspire 5100

[Big Tone]

Hi all, I have a problem with not getting any sound from my centre speaker when playing music. Not sure if this problem occurs with games as I don't play any. I'm using SB Audigy card & Inspire 5100 5.1 surround speakers. I have found if I disconnect the analouge/digital lead from the sub the centre speaker comes on but when I do the test like this it has dissapeared again.
Please help.

[Tiretool]

Have you made sure that you've got Windows set up to recognize that you're actually using a 5.1 speaker system? I know that in XP, if I go to Control Panel, Sounds and Audio Devices, and then click on Advanced, you can select what type of speaker set you have.

[Big Tone]

Yeah, I've done that already

[Big Tone]

Not sure if this is absolutley correct but maybe someone here can confirm it. I have picked up from the sound blaster forums (http://de.europe.creative.com/support/forums/thread.asp?thre=24891) that to get full dolby pro logic from a stereo source I need to use digital speakers like the creative inspire 5500's other wise I will only get 3D surround which doesn't use the centre speaker. Maybe someone has had the same problem and can confirm this for me before I go spending more of my hard earned on another set of speakers.
Cheers
Tone