Pioneer DV360 Dolby Digital acting wierd

I just bought the Pioneer DV 360 and for some reason it is acting weird with my Surround sound speakers (Acoustic Solutions DX333). Basically I cant change the volume using the credit card size remote. When I turn it down it goes all the way to the bottom and the sound vanishes. Then you cant turn it up again without hitting standby.

There is NO Dolby Digital LOGO in the DVD players display even when using 5.1 discs. I had a PS2 and then a Cyberhome 450 before this and had no problems with it. Any ideas?