I've come across a strange problem today. I recently rearranged my computer setup to a standing desk in another room, which in fact is even closer and in direct line of site to my Apple Airport Extreme. I noticed once yesterday, after setting everything up and once again this morning when I woke the computer from sleep, that my internet speed was horrifically slow (2.88 MB/s as opposed to the 50+MB/s I normally get). In the same location, on the same 5GHz wifi network, I ran Speedtest on my iPhone 5S and got the 50+MB/s I was expecting. Now I've been using this exact same setup (External Monitor, Apple BT keyboard & mouse and Belkin Thunderbolt dock) in another room, with no problems with internet speed -- all while plugged into the AC adapter of course. I've gone through a bit of trial and error: unplugged everything and use the MBA on the couch - fast internet. Later, I had everything plugged in on my standing desk and tried a series of steps: opening screen from clamshell mode (slow internet) keeping everything plugged but moving MBA closer to router (slow; ext monitor not causing interference, I assume) unplugging Thunderbolt cable but leaving AC adapter in (slow internet) then unplugging AC adapter (fast internet). What?! Now, if I then plug the AC adapter back in, my internet seems fine. I'm typing this write now, all plugged in, and just got 56+MB/s down. The only thing that's really changed in all this is the electrical outlet I'm using with my surge protector/power strip. Could that be causing an issue? Otherwise, I'm not sure what's going on, considering everything's fine after re-plugging in the AC adapter. Thanks!