|Try relocating the router if only by a few feet. It can make a difference as it might be in a bit of a dead spot at the moment.|
As for the power-line Networking, it is something well worth looking at. When power-line networking first came out it was a bit unreliable but the bugs have been ironed out and it now works very efficiently. I have been using one for about six months now and it has never given me a moments trouble which is more than I can say for wi-fi.