HD DVR w/ HDMI Reciever

Hello all,

I have the HD DVR from verizon and a Yamaha HDMI reciever. I want to hook both my blu-ray and HD DVR w/ hdmi through my reciever, however whenever i do this my SD channels are reset to displaying them with black bars on the side ( "strech" mode is turned off). When i connect the HDMI straight to my tv, the "stretch" mode stays and i have no problems. Has anyone come across this issue? and is there a fix for it?

Thanks