Hi, So I've been having this problem since a while not and I beleive it's not normal. Basicly, any serious amount of HDD activity (this is mostly noticable when I'm unarchiving large .rar files for example, or watching a big 720p video AND trying to do something else i.e. browse the 'net) hangs the system totally. Now, I do realize that HDD activity does slow down the system to a certain degree, but this is not it: I'm talking about the whole system being totally unresponsive for 5-10 seconds, sometimes even the mouse freezes. Any ideas? This happens both under OSX 10.5.6 and Vista Ultimate SP1. TechTools Pro hardware tests say the computer is okay. Thanks, KTamas p.s. I have a black macbook 2.1 - that's the last one from the non-santa rosa, GMA950 series.