Hopefully someone can help me here... I have a Sony BDP-BX57 Blu Ray player connected up to a Sony STR-DG720 receiver through HDMI. Currently I only have 2 main speakers connected, the receiver set up in 2 channel mode. For watching TV from my DVR, for playing music, it's fine. For playing regular DVD's through my Blu-Ray, or for streaming internet content, it works fine in 2 channel mode as well. However, whenever I put in a Blu-Ray disc, the receiver reverts to Surround Sound mode, so I only get part of the sound through my speakers, no dialogue. I cannot figure out a way to force the receiver back to 2 channel mode, from either the receiver or the Blu-Ray. Has anybody else heard of this problem? Any help would be appreciated.