On the Audigy Surround Mixer page you should have "digital output only" checked, if you don't you aren't getting a digital signal through the single digital output wire. As I said before, you have to make sure you Dolby Digital on the "DVD" itself enabled. When you first start the DVD you should get a menu on the screen that reads something like, play, audio setup or maybe language instead of audio setup, and several others. Go to audio or language and set it for Dolby Digital or 5.1, whatever is listed. If you have this set to PCM stereo, you'll get Pro Logic only. If you don't have a manual setting on your reciever for Dolby Digital, then leave it on Dolby Pro Logic and it should auto detect the Digital signal.
Set the large/small speakers settings like the manual says, but for sure turn off the subwoofer, or you will get very little bass, at least until you get one.
As far as EAX on the sound card, I would leave that turned off, as well as all the other surround parameters on the card and just use whats on the reciever. You shouldn't have two surround parameters going (the card and the reciever) at the same time.
A personal opinion, I don't like any surround turned on, except when watching movies or tv (Dolby). I don't like it for music, although Dolby Pro Logic II Music may be OK, I don't have it. Most of the other surround settings on your card and reciever to me sound fake, except for a very few. As far as EAX or EAXHD, I don't like it except for some games like SOF II on which it is great. Again, just a personal opinion.