I have never heard of that brand, nor could I find any information for it online, so I can't help you specifically. I can try some general help, though.
In your post you said VCD. Did you mean DVD? If you really did mean VCD, then you should know that VCDs do not play back inb Dolby Digital. This could be why you are only hearing you main speakers.
Most 5.1 receivers have different playback modes. Many of them don't switch modes automatically. Look in your manual and figure out how to activate the surround or 5-channel stereo mode. That should activate the other speakers even if the source material is stereo.
