Okay. I found out the problem. I was initially NOT using PowerDVD 8! It was the crapy software that came with the HP laptop - some HP Smartmedia player or something. I uninstalled that crap.
Next, I installed PowerDVD 8. On speaker configuration, I got a choice of "HDMI" or "5 speakers", "6 speakers", etc. I picked "HDMI".
On Audio output configuration, I got a choice of either "PCM" or "DD/DTS Passthru".
I don't know if PCM includes DTS-HD & TrueHD. I played with both options, but could not hear any differences. So I just went with the DD/DTS passthru. This way, I KNOW what I'm hearing because my Denon receiver says "Dolby Digital" or "DTS Surround".
So how does it sound NOW?
It sounds GREAT.
I really can't tell the difference between this sound versus the sound from my Denon blu-ray DTS-HD & TrueHD.
I saw "DOOM" BD on the laptop. Picture was great. Sound was awesome. Bass was INSANE!!! It literally rattled my bones.