Have you tried a 5 GHz device? I'm running N-spec, and when I threw an airport express into the mix it met my expectations. My initial setup involved a WRT600N on my Premiere, and a WGA600N on the Mini. That gave me the random V67 or V87 disconnect error. I tried to run N-spec on the 2.4 GHz band, but got warnings that my network was too slow. I'm not streaming HD content. I've had good results with the airport express hard wired behind the WRT600N creating a Mini only network on the 5 GHz band. I just reconfigured my network making it more linear as opposed to triangulating the line of sight and to my surprise it still works. The WRT600N is on a 2 tuner Premiere, the Mini has the airport express behind the WGA600N, and the terminating end has the 4 tuner Premiere connected to a Tomato WRT320N.