Reciever Silent After Channel Shifts

So, I just bought a Pioneer VSX 819H-K. I am using it to take the audio playing on our home theater computer out into my take classic 5.1 speakers. Everytime I change the channel from BluRay(the HDMI input I have my computer plugged into) to tuner (the only other sound source I have) and then back again it no longer plays any sound. Sometime it also does it when I turn it off and then on again, but only sometimes. Turning my computer on or off has no effect.

Sometimes the problem is fixed by me unplugging the HDMI cable when everything is going and plugging it back in. Sometimes it doesn't. Sometimes when that doesn't work, changing which HDMI input it is plugged into helps, but sometimes that doesn't seem to work right now.

I would settle for just the one channel (computer) working, as that is all I am using it for in the long run, but I can't leave the receiver on 24 hours a day. Please help me. I am starting to lose my temper and my girlfriend is judging me.