my MBP is 1.5 years old. it didnt start acting up until the beginning of this school year. sometimes it would freeze and i cant move the mouse cursor or anything. i have no choice but to press power button and restart the computer. this has happened 4-5 times already for the past 1.5 years. is this normal or do i have something suspicious going on? i have been watching movies online from websites that always give pop-ups. can this be from virus or some malware? also, is there a way to block pop-ups in firefox? i have the pop-up blocker in the browser itself enabled but is there another plugin or something like that that can work better?