I'm having a very similar problem. My macbook is showing 100% - Battery Charged, Power Source: Power Adapter. It keeps saying that until the battery dies, doesn't give me the reserve battery warning. It's been like this for a few days now, even when I've plugged and unplugged it multiple times. I was hoping it would somehow reset, but no luck. The battery meter on the side of the laptop seems to show the correct battery level, however.
And saying that this isn't a real problem, but is a problem with a 'bootleg' laptop isn't really advice, it's an avoidance of giving advice. My laptop was delivered straight from Apple and I'm having the same issue.