My girlfriend recently bought me a Motorola Razor v3 cell phone. It works fine usually. On many occasions it tends to shut off and reset or stay off completely. I say this happens at least 2-4 times a day. The battery is usually fully charged or I keep it connected to the charger. I dont use it too much, but sometimes I may use it for 15 minutes or less. Is this common or do I have a defective phone? The phone is about 3 months old.