I have been experiencing trouble with my Treo 600. every once in a while I will hear a short tone and my screen will say my battery is critically low and will shut down in 30 seconds. When it shuts down I will try to turn it on again and the screen will fade out. I am sure it has had close to full charge. I can plug it in and some times it will immediately start to charge and show the battery of high level as I expect. Other times it will show a full green battery with a red X over it. I have done much research but have found no explaination for this red X . I have done a cradle reset. The problem will still occur.