Beacon stuck solution
Hey gang. I know several of you have struggled with the stuck beacon on certain Atheros controllers so I thought I'd share my experience. I chased down all the forums on pfsense and freebsd and the solution is simply to get a different wi-fi controller.
I happened to have an old MacBook Pro that died so I took the wireless controller out and swapped it out with the unit in my pfSense box and it worked flawlessly.
My pfSense box is an Acer Aspire One GZ5 which is an early adaptation in Aspire One series. It sports an Atheros wireless controller that simply isn't supported by the driver packaged with freeBSD. I think it's safe to assume that all those dealing with the stuck beacon issue are dealing with the same compatibility issues I observed. FWIW, the card I used contains Atheros chipset AR5007EXS which is an A/B/G adapter part number AR5BXB6 which can easily be had online for south of $20.