Jeepers! Well, I hooked up this connector as a matter of course -- not with the fat-ass cpu fan, cause it's too big but with another system fan to save space. Anyhoo, perhaps you should also plug one of the small exhaust fans into this port if you have a three-pin connector available. I've been reading A7M266 threads for six months now, and I haven't heard anything about this issue. There's a very active forum at amdmb.com (asus mboard), so that's where I'd look for the definitive answer if the clever-boots around here (and, indeed, they are quite clever) don't answer first.