Sound but no voices

[Westchester]

I have a PS3 connected to a Onkyo TXSR605 receiver with a Panasonic TH-50PZ700U Plasma TV. I have encountered a few issues with the setup and could use any input from the community please.

1) Is it normal for the receiver to randomly switch off and loose picture sometimes to reset? It is completely random and not sure what it is doing. Sounds like it is switching channels sometimes. We have only 3 speakers and a velodyne sub attached to the receiver.

2) Our main issue. We are trying to watch a Blu-Ray (Fantastic Four Silver Surfer) on the PS3 and we get the background noise which sounds great, but when the characters speak, it is basically mute, or blurry noise that is extremely soft. We have no idea why that is. We use HDMI from the PS3 to the reciever --> and then we have another HDMI going from the receiver to the TV.

Thanks in advance for all your help and responses.