Yamaha rear-out problem

I’ve got an Yamaha X-Wave 6000. The model is YMF 754-R, or at least that’s what it says on the chip on the card. I wanted to connect another set of speakers to the REAR OUT to have some surround. Unfortunately i can’t get that rear out to work.
When i was using Win98 with the drivers from Yamaha there was an Yamaha Control Panel in the windows cotrol panel. Now i’m using WinXP and no matter which drivers i use (the windws standard or Yamaha) the rear-out doesn’t work. With the yamaha drivers for WinXP i do have a Yamaha panel but no setting for the rear-out. I also tried to set my speakers as Quadrophonic Speakers in the sound options - nothing. The AC3 filter also doesn’t manage to get it to work when i set it to 2/2 surround.
The only reason i can think of right now is that the drivers are probably not for the EXACT model, but i’m not sure.
Please give suggestions.
Thanks in advance!

To add:
I found out that the newer drivers don’t support 4-channel audio. So i installed the 2234 version for Win2K which support it for sure. With those drivers the 4-channel option appeared in the Yamaha Config panel in the windows control panel, but it was dimmed/greyed and cannot be selected.
Is it possible that there ISN’T ANY way to have 4-channel audio on WinXP?
In the readme file was written that i should select the appropriate INI file for my sound card. I selected the one with AKM4543 codec. There were few others but only this was supposed to be 4-ch. Also in the INI file itself was written to: ‘’ ‘do’ the ‘special’ settings and add the AKM4543 settings.’’ I have no idea what this means exactly.
Does anyone has had such problems as well?