I've had my 671 for quite a while ago and recently I moved across country. When I got into the new house and set up my home theater I started having a couple issues with the 671, I think. I was hoping someone could provide some insight on these issues and give me a couple suggestions.
1) When controlling the receiver through the network (device web page) I often lose connection with the receiver. Same thing happens when the Android App on my phone. I generally just have to wait for the receiver to connect back to the network. I've got the receiver hooked up to a Cisco/Linksys hub which is connected to a Cisco/Linksys wireless extender. All my other devices seem to be working just fine on the network.
2) The big one, that's driving me crazy. I have a Klipsch 12" powered subwoofer hooked to the Subwoofer connection on the receiver. The subwoofer, however, constantly powers down because there's no signal coming from the receiver. When I run YPAO I get an error saying the subwoofer is out of phase, but I tried YPAO four times, two switching the subwoofer's phase switch both 0 and 180, and changing the receiver settings to normal and reverse. All times when YPAO runs sound barely comes out of the subwoofer at all. You can hear a very muffled rumble when it's testing the subs sound levels. I turned the Crossover on the sub and the receiver up to 120 hz and the gain on the subwoofer all the way up to 10. For music the subwoofer works just fine, however when the receiver it set to a cinema mode I get no sound. It's rather irritating to say the least.