Minor Problem with MagSafe Power Adapter

Question

I got my MBP almost a year ago now (partially why I'm asking the question) and I've noticed that my power adapter doesn't always show the charge light. Sometimes it is not on at all, and sometimes it is less bright in color (both green and amber).
If I remove it and put it back it usually corrects itself.
It if fully functional; even if the light is completely out and plugged in it still shows as charging.
So, is this normal? I never remember having this sort of problem with my PB G4.

Answer 1

I would think the led light on my adapter cable was broken, but I discovered it works fine on a co-workers MBP. His adapter, which we know works, does NOT work (ie. the led does not come on) when attached to my computer. This indicate to me that the problem, whatever it is, can sometimes be with the computer and not the adapter.
I would be curious if others with apparently dead leds have tried their chargers on other MBPs.
Here's the long version of my story:
My 5W MagSafe completely fried after only 9 months.
The new adapter was fine for several days until this morning.
My "low battery" warning popped up, so so I plugged it in to recharge and immediately noticed the little led on the charger cord did not come on.
I found it hard to believe that I had another bad adapter, so before making the trip back to the store, I went into the studio where there are some other MBP users.
I plugged my adapter into another laptop and the led came on. It appeared to function completely normally. I tried MagSafe adapters from two other MBPs, but the led did not come on on either of them while attached to my computer.
This made me think there was some sort of problem with the connector on the computer itself. Just visually, it appears to be clean and corrosion free.
The next obvious step, it seemed, would have been to try swapping batteries with the other laptops, but mine is a 17" and everyone else here has 15"... and so we have different battery sizes.
One of the people here at the studio had a little utility called "Coconut Battery", that reports information about the battery health. When I ran it on my laptop, I got what I thought were rather surprising results.
It showed the usual things like current charge (21%), battery capacity and so on. But under "Additional Info" it said "Charger connected: Yes" and "Battery is charging: No".
I figured this narrowed it down to a problem with the battery. But as I was showing these results to my co-worker, the "Current Battery Charge" changed from 21 to 22%. Huh? We left it plugged in and it continued to show a steady climb in the charge, as if it is working normally. Except there is no led light, and the software still says it is not charging. Odd.
I then noticed that the built-in battery level indicator on the status bar was also showing the same increases. The led lights on the back of the battery are indicating an increase as well.
Just out of curiosity, I ran a second battery health analyzer program and again got these conflicting results. This one reported the same battery charge and capacity and so on as the previous one. It also recognized that the laptop was running off of AC power, that there was a battery, but it said "Not Chargeable."
So now I am going to let it continue until I have a full charge and then see if the computer will run as usual from the battery.
I don't think the store here is going to give me another adapter since this one appears to work just fine on the other computers.
Any thoughts on why the led would work on other laptops but not mine?
Why the battery health monitors report that the battery is being charged, but also that it is "not chargeable"?