DVD Audio Low/CD Audio fine

Hey all,

Been having a weird situation ever since I put this setup together. First the components:

HTPC:
Intel Core2Duo E6600
Gigabyte GA-965GM-S2
2x1GB RAM (don't remember the brand)
ATI Radeon HD2600Pro
BlueGears b-Enspire sound card
LG Super-Multi Optical Drive

Receiver:
RCA Rt2770 5.1 Channel (This looks like the one).

The HTPC is connected to the receiver using a TOSLink Digital cable from the BlueGears b-Enspire sound card.

Here's the problem: When I play a CD or MP3 on the HTPC, the audio is fine. To get decent volume, I only have to turn the volume up to around 20 (half way), but if I want to get the same volume level when playing a DVD (or DivX movie), I have to crank it all the way up to the 32-35 range. I've gone through all the settings on the sound card's control panel, but I don't see anything that's specifically for DVDs.

Setting options in Oxygen HD Audio Configuration (control panel for the sound card) include:

Dolby Digital Live (current setting)
DTS Interactive
Digital Audio 44.1 KHz
Digital Audio 48 KHz
Digital Audio 96 KHz
Digital Audio 192 KHz
S/PDIF in Loopback

I tried each of these settings but noted no difference in audio output while playing a DVD. It seems I'm missing something, but have no idea what it could be. Any suggestions at all are welcome and if you need any additional info, please let me know.

Thanks in advance!
-Wolf sends