Computer recognizes new healthy battery as dead, but still works

Question

I just got a new healthy battery that is fully charged, but my Macbook recognizes it as dead. I can use my Macbook without a power cord and it works, but the computer says that it is dead. I can't turn it on without a power cord. Why is it doing this?
Sidenote:
My airport works for about 5 minutes and then goes away. I got the wireless card replaced but it still does this? Are my computer problems related?
Why is my computer not recognizing a healthy battery and a healthy wireless card?

Answer 1

No satisfaction from Apple, so I had to take matters into my own hands. I knew the battery was new; I had unwrapped the shrink wrap myself. I knew the battery had no moving parts. The battery contacts looked clean.
OK, I took the battery in my hand and slammed it down flat on my desk and wacked it on it's sides for good measure.
When I put it back into my powerbook , it started charging - first one light, then another until fully charged.
Try it.