Low volume levels when using BlackMagie or Elgato software

I'm having a strange issue on my MacPro using the BlackMagic intensity pro and/or the eyetv hybrid.

If I try to use either of them just to watch TV (via their own software for just watching the incoming audio/video), the sound levels I get out out of the built-in speakers on my Samsung 2493HM display is very low. I have to push the levels of the application, the Mac OS output level and the volume setting on the display to hear the TV input sound. Naturally, this makes any other sound coming out of my Mac very loud. All other sound coming from Mac through my display's speakers is absolutely fine and works with no problem at all.

The connection to the Inensity Pro card is via the breakout cable, (YBR, RCA LR) and the connection to the Hybrid has been either direct coax connection or breakout with S-Video and RCA LR).

I've contacted both manufacturers and confirmed all the settings are correct. The video for both products works fine. In addition, I've captured video/audio via the BlackMagic solution using FCS 6 and that works perfectly, using the video in various projects.

I started my Mac in Bootcamp and installed the BlackMagic software for Win XP, but got the same results using the Blackmagic player in Mac OS X 10.5.

One last thing: My Samsung 2493 has an HDMI input which I use connected to my cable box for watching TV when the MacPro is turned off. With this setup, I get proper sound watching TV.

Any ideas or suggestions? Thanks.