Nokia n95 frozen screen!!!?

My n95 turns on ok, I enter the pin number and when it loads the screen goes funny and automatically loads up the main menu. I can navigate around the menu but cant get to my normall screen. after about 2 minuets the whole phone freezes. any suggestions to fix this. It started yesterday when I switched my phone off, the problem started when I switched it back on. I have tried taking the battery out hundreds of times and also tried to restore factory settings but soon as I go to factory settings the phone freezes completley.