Blu-Ray doesn't play all dialogue. I have Denon receiver set for stereo, but the blu-ray is not playing all the dialogue.

Appears to be a software problem. Unfortunately, some blu-ray players contain software that expires, requiring you to repurchase newer, more expensive software from the manufacturer in order to continue to play blu-ray discs. Check your software for the player. No freeware blu-ray software out there.

Is this a copy of a movie?

Be sure in the menu setting that the audio analog/digital setting is correct for the blu ray setting. All try the factory reset as stated in owners manual

The Denon DVD-2500 will not play Blu Ray disks - DVD and CD only. Make sure you're using the proper disks.

The Denon DVD 2500BT however, WILL play Blu Ray disks.

Which do you have?

do you have a center channel speaker hooked up? Most dialogue in movies should come from the center channel.

The Wii doesnt play Blue-Ray "BD" Movies, only the PS3 does, also the Wii doesn't play DVD's.
You can get the Wii to play DVD's by cracking the system by placing files on a SD Card, but your Wii will never play Blue-Ray movie because the system doesn't have the blue laser in the cd drive, sorry.

Have a nice day

You need to do digital input assignment. Go to SETUP, DIGITAL INPUT ASSIGNMENT, set OPTICAL 1 for your input (DVD).

Yes select audio optical out on your Blu Ray Player under Audio settings and make sure the Denon is set to Optical or Auto in. You should be set to go

For DENON DVD-3930: In "setup", HDMI sound settings have to be "2-channel". Then SACD 5-channel output is enabled.

Simple thought... are you trying to play a Blu-Ray Movie disk on a Denon that not Blu-Ray Compatable? That would do it.