Laptop Battery ProblemFollow

So, about a week ago, I suddenly started having a problem with my laptop's battery.

(Sony VGN-NR498E)

Well, when I plug it in, it'll charge for a little while and then just stop. The PC will tell me that it is still charging, but it'll slowly eat away at the battery's life instead (while plugged into the wall) and the graphic would stop moving. Well, that's what it TELLS me is happening.

As the battery was working fine before now, I have trouble believing it died. It never showed any of the symptoms of it. It always would charge to 100% at a normal pace, for instance.

Unplugging it and putting it back would restart it for a while, until today. It just ate its way down to 0%, stopping only to "charge" for 4 revolutions of the animation each time I unplugged it.

Note: When I'd unplug it at 0%, it would shut off due to an apparent lack of power.

Then, all of a sudden, it has 100%. It was having the issue, I unplugged and replaced it and the power tray says it is full.

I don't really get what's going on... Has anyone experienced something like this before?

I think it's a programming error...

Because, when it suddenly showed up at 100%, it was actually at 100%. I took it to class and it lasted. It had been showing 0% before that.

Sony got back to me (fastest customer support reply email EVER) and told me a few things to try.

So, we'll see.