Quote Originally Posted by jadnashua View Post
I don't like the spring-loaded, back-stabbed outlet connections. There are some that you can insert in the back and there's a screw clamp that tightens them down - those are fine. Especially if that receptacle gets a high load, the less than ideal contact of a back-stabbed unit means heat, and over time and cycling, the spring tension can decrease, making it worse.
Echoing JIm on the old back-stabbed receptacles; if you're having circuit problems, just go ahead and remove all of these. In my limited amateur wanderings, I've seen at least half a dozen of them with wires hanging completely loose, and others that failed completely but still looked okay. The new back-wire receptacles that tighten with the terminal screw are great, and would be a very easy replacement. Even if the old ones are working now, they're a high risk to fail in the future.

And along the way, like Rick said, look for wire nuts with multiple wires; easy for somebody to goof on. I have in the past...