This probably seems a bit ridiculous, but after having my first power supply melt and short out on me I've been completely paranoid of this happening again. My first power supply was one of the older models from 2006. I then got it replaced by one of the newer smaller models. After about a half a year it started twisting around on the inside of the cable which got me worried. The apple store wouldn't replace it unless it was melted so I called Apple and got a new one. I've had the newer one for about a year and the cable seems to be wrapping around itself on the inside again. There doesn't appear to be a place where it's melting or breaking. I take care to not wrap it too tightly. Using it as a desktop replacement I'd like to not have to worry about leaving it plugged in when I'm gone. I find it crazy that this is even an issue but after having the first one melt right in front of me I find it hard to trust. Are the newer power supplies any better? Is this not an issue anymore?