My Dell Inspiron 1150 charges intermittantly

I have a Dell Inspiron 1150. It seems to have a mind of it's own when it comes to charging.

I'll be using the laptop, and suddenly, although fully charged, the "on battery power" icon pops up and slowly the battery runs dry. I've tried restarting it before it goes dead, but it doesn't help at all. I've also tried to take out the battery and try to power it simply with the adaptor, and it doesn't work either.

The real crazy thing is that once it does die out completely, the charging light comes on and it starts to charge. It seems like there's a sensor that lets the computer know when to charge or not, and it's bad.

I've tried getting a new power adaptor but it still does the same thing.

Since this computer was so mass produced, I have to imagine I'm not alone with this problem.

Can someone help? Thanks!!