Hey, I just got a refurbished Macbook pro last week, and it ran fine until a couple days ago. It started to freeze at random times, with little or no programs running. Also, it rarely boots up. I hit the power button and the little light shows that the computer is on, but I get no logo or startup noise. and other times, it beeps this loud tone several times. Anyone experience something similar to this? I have a 13" Macbook Pro with 2.53 Ghz processor, 320 GB HD, and 4GB ram with Snow Leopard. I have not done a fresh install of the OS, but I do have the disk if necessary. And its also under warranty.