OR ...you have to reset the battery "fuel guage" Here's a post from an Imacon site I participate in. It worked for me when I had the same problem ...
Probably the so called "fuel gauge" is out of sync in your battery Please find below a procedure to reprogram batteries.
1. Upgrade the camera to latest firmware
2. Charge the battery to full capacity (charge between 4-12 hours, don’t care about the flashing l& of the charger)
3. Without attaching the fully charged battery, press the red ON/OFF button on the upgraded camera (to totally discharge all voltage in the camera).
4. While pressing the "Menu" and the "Flash" button at the same time, attach the battery to the camera. If you hear a beeping sound, the re-programming of the battery is successful, otherwise repeat steps 3-4 until the sound is heard.
5. Camera and battery is now ready for use.