On my Dell Inspiron 6400 I get plugged in not charging on the battery indicator. I recently upgraded to Windows 7 and also changed out hard drive and battery. They all work properly. The battery was shipped to me and had 63% charge. I put it in and unplugged to make sure it worked fine and then plugged back up to fully charge as instructed. I now get the plugged in not charging. It looks like a lot of people has this problem as I goggled it and tried several of the suggestions listed and none worked. Any one else been able to find a fix.
It sounds like we're haveing the same problem. I'm on my 3rd AC adapter and have replaces the motherboard with no luck. I've sent my computer to the company and they said they could find no hardware problems with the computer. Everything, like yours, says it's working properly. It doesn't say "plugged in not charging" though; it just stops charging. Even though it's fully plugged in. Now they're saying if all else fails then I need to get a new battery, which is where I'm at now.