charger or battery problem...?

I have a strange situation. On the weekend I was charging my macbook pro and the icon on the top would go from charging and how long it would take to "Not Charging". It took forever for it to charge and the light on the adapter would change from orange to green (when it said it wasn't charging) and back to orange. Once it fully charged it was fine, the light stays green and I was able to plug it in without the problem at least 2 more times. Today it happened again but I wasn't able to call Apple till it was fully charged. The guy I got just started trouble shooting, but I'll have to call back if it happens again.

Has anyone else had this happen? What's going on? I was hoping Apple would have known what the problem was...I think a former roommate had this problem at one point. On the bright side I didn't have to wait at all to get through, I was transfered to a person right away I love not being on hold for an hour and a half AND whether its the charger or battery everything is still under warranty so it can be replaced

Called apple again. After about a week the 'not charging' has come back. They said its probably the battery. Since my mac is over a year old they can't do anything about the battery so I'll probably have to buy a new one soon boo