Re: trouble with rear sprocket/chain
Here's one thing I noticed today. If your rear chainstay is angled outwards as it goes back towards the wheel, you may have issues. The tensioner will be at the same angle of the chainstay, and this makes the chain run at an angle across the tensioner wheel. If you adjust it so it's quiet, it takes the chain off the sprocket.
One solution would be to "twist" the bracket. I tried to do it with a couple pair of pliers today but failed. Need to figure out a good way to do it.