I wanted to purchase a new av receiver. I wanted to get the Onkyo TX-NR646 but I've done some research and found out that a lot of people are complaining that the Onkyo receivers start having technical problems after a few months of use. They say there's a problem with the HDMI board and loss of signal when connected to TV via HDMI cable. Does the problem get solved if you do a firmware update or does it still occur even after the update? I don't know much about av receivers as I've never owned one but I'm considering to buy one and upgrade to a 7.1ch surround sound system. If the Onkyo receivers have a lot of technical issues then I'll get the Yamaha RX-V677 receiver as it's the only other option available. If anyone has owned an Onkyo receiver and has faced such problems then please tell me about it and also if Yamaha is better than Onkyo.