mkrishnan said:
...as nice as MagSafe sounds, no one's traditional power cable is melting anything.
I had a "yo-yo" style power connector at work that developed a short from cable stress near the point where the AC cord meets the disk. Move it around a little, and you could see blue sparks inside, and it was easy to see where it had slightly burned the rubber internally. Only a matter of time before it started a fire.
And yes, that had zip to do with the connector port, but point is there's plenty that can go wrong with the old style, too. I'll also mention it was DRASTICALLY easier to accidentally short the old ones than the MagSafe ones before you plug it into the computer.
Back to the main topic, I'm STILL not seeing what you're describing in the photo you posted, but I'll take your word for it. Regardless, it sounds a whole lot more like an internal heat issue than anything to do with the MagSafe connector--if it were the connector, it'd be melting from the inside out, not where it contacted the case.
And the temperature you mentioned is, I believe, the internal thermal limit of the Core Duo--it's designed to run that hot, but it'll scale back its own speed/voltage to prevent overheating at that point. Intel's chips have been pretty good about that for a while--they generally won't even crash (or, quite literally, burn, like some AMDs) if you remove the heatsink from a desktop processor, just slow way down. If it's crashing on you, then the heat may be being generated by something else, so that even when the Duo scales back it's still not cooling enough.
Does sound like you've got a problem, but I doubt it's the MagSafe connector.