That's kind of what I thought too. The first time I did it, I had the PS3 turned off but I forgot to unplug it. I don't think it messed anything up though. The 2nd time I vacuumed the vents, I made sure to unplug the system. Anyway, neither time seemed to do much for the fan. I really don't think it was that dirty to start with since I keep mine covered when I'm not playing it. It's just weird that all of a sudden my fans have started to kick in to that louder mode almost as soon as I start playing anything. It used to take at least 25-30 minutes for that to happen before. Like I said in my earlier post, the system still seems to be working fine. Other than the fan being loud and going into the higher speed quickly, I've not noticed anything else going on with it. I'm just trying to figure out what's causing it now and if it possibly might be a sign something's getting ready to go wrong with it. It has me paranoid now every time I turn it on and hear the fan get louder. It's still nowhere near the 360 noise though.