So I'm trying to connect my MBP to my new Belkin Double N+ (F6D6230uk4) router. I have 2.4 ghz set to b/g and 5 ghz set to n and 20/40hz bandwidth. Last night, when I connected to the router for the first time, I was showing 300mbps, when you Options+click the Airport icon. However, now I'm only showing 145mbps. To be fair, I may have changed a few settings between now and then, but I have no idea how I was able to get 300mbps before. It's as though it's only connecting to one channel, instead of two, which is required for 300mpbs I think?