X61t wont boot with ac adapter and battery together.

[Stevesoura]

Having a problem with my x61t. Hopefully someone can help. Had my x61t for a couple of months without any problems. Today, I tried to boot it up and nothing. I then removed the battery and ran it on ac adapter only. It booted just fine with no problem. I then inserted the battery and it went completely dead. I thought it was a battery issue but then only booted the laptop on battery alone. Just running on battery alone, it boots up just fine. I then inserted the ac adapter and it goes dead again. Has anyone experience this?