It might be fixed "playing" w/ your ACPI software: try to uninstall every single bit of ASUS's crap (i. I believe that there's a problem with PCI-E Port used for connecting your WLAN adapter to PCI-E Root.
Because the brand name is cooler, I guess? Their hardware makes its job, the software's being updated monthly (you can always get the recent version on Station-Drivers). I personally have never had any sort of problems with Atheros products, since the very first AR5000 Series hardware many years ago (2004), and that's not the first time I hear people are going rough on Atheros, while praising Intel for. They had a page dedicated to drivers (before that deal with Qualcomm, now it's back, but only contains Ethernet NIC software).