Be cautious about the Magsafe adapter
they have no known problems that I am aware of
I caught mine just before it started to melt!
I bought my Macbook in June. A couple of weeks ago, I would notice that my Macbook would drop to battery power even though it was plugged in. The little light on the magsafe would be off and the charge indicator on the top right of the screen would show that I was on battery. I would then unplug the magsafe adapter and then plug it back in and the light on the adapter would come back on and the battery was charging again. I didn't think anything of it at first, but wanted to keep an eye on it since in the back of my head I'm always thinking about other peoples problems they had with their magsafe burning up.
The problem started happening more frequently in the past week. However, over the weekend I was working on my laptop when I saw the screen on my macbook dim (the first sign that it was running on battery.) And sure enough the magsafe light was out and the laptop was on battery. So I went to pull the magsafe out and it was RED HOT!!! I mean, not just warm, this thing was HOT, I had to pull it out by the cord. I immediately unplugged it from the wall and my Mac and let it cool.
The next Day I went to the Apple store, and while I was standing at the Genius bar waiting to be next, the guy in front of me started explaining his problem and it was the EXACT same problem I had. Then the Mac employee then went into the stockroom and I asked the guy what he was experiencing, and he told basically the same story as me. When the employee came back, he said that they dont have anymore of the 60 watt adapters in stock, only the 80 (or 85 whatever the Macbook Pros use). He told him they will be in stock in a couple of days and they will call him.
Then it was my turn and I told the employee that I was having the exact same problem as the previous guy. The employee then checked out my laptop and adapter and tried pulling on the cable but of course could not duplicate the problem. But without hesitation, he said they would replace it an they will call me to come in and pick it up when the new ones arrive.
This problem has been found by many others (google Magsafe and you'll see what I mean)