i had my pb for close to a year and it started have a weird trackpad problem last week. occasionally, the trackpad will stall and i can't move it around. if i keep trying to move the cursor it will work slowly start to work after about 10 seconds. has anyone had this problem? and anyone know why this happens? i am very careful with my pb so i'm guessing it's just bad luck. and will apple replace the trackpad or fix it since its still under warranty? thanks.