One out of five times I slide close my Pre it shuts off complete. I love the WebOS but after my 4th Pre I am truely a believer that it is the cheapest buit device ever!!! I'm sick of showing up to the Sprint store to replace it. They won't give me a new one anymore and I don't think they like me anymore. If you're looking to buy a Pre I would wait for the next version, or the next phone with WebOS. Palm and Sprint brought a knive...ok maybe a sword to a gun fight. The Pre will never beat out smart phones like the iPhone.
Ok, so we all know why it shuts down. Its from the jolt of the slide closing cutting the connection to the battery.(the battery is a tad to small for the battery compartment) What can you do? Wedge a couple pieces of paper above the battery between the battery and the battery compartment. This will solve the problem very well. After i did this i couldnt get it to shut down when i closed it ever again. Then call palm and request a new battery like i did and i will recive a new battery in about 3 business days. Talk to a supervisor cause the regular technicians had no idea what the problem was. I had to research the problem myself. www.fitnessdeeds.com
As stated above the issue here is not the phone itself it is the battery. The original batch of pre's shipped with batteries that were made in Japan and are slightly too small. What you need is a new battery that is sized properly. There is an easy way to tell which type of battery you have, on the bottom near the contacts you will see something that says Cell Origin (either Japan or Korea). The Korean battery is the properly sized one and thats what you need to get.