Hello all, I'm having some problems with my recently purchased Macbook Air concerning its ability to work with USB devices. Here is the story: I am a long-time DJ who has recently decided to take his set up to a more digital domain. So, I traded in my 7ish year old MBP for a new MBA (13 inch, i7, 8GB, 128GB SSD) recently in the hopes of creating a smaller, more portable, modular setup. To do so, the MBA needs to work with 3 USB devices: 2 MIDI controllers and 1 external HDD. The HDD is a WD Passport 1 TB. The MIDI Controllers are a Traktor Kontrol S4 and an Allen & Heath Xone:K2. Originally, my plan was to run all these devices through an externally powered USB 2.0 hub. However, when I did so, anywhere from 10-60 mins into playing music, the USB devices just stopped working. They still had power (the S4 is externally powered in addition to the externally powered USB hub) but they could no longer control anything. The S4's usb connection indicator was flashing, signalling no USB connection. In addition, the HDD was technically "mounted" but, when clicking on it in Finder, it's as if nothing is there. I got no message from the MBA saying anything about too much power being drawn or devices being ejected. It just stopped working. So, my first thought was it was the USB hub, as it was older. So, I connected the S4 and HDD directly to the USB ports on the MBA. Once again, the same problem occurred. My next thought was that one of the MBA USB ports was able to put out more power than another (I'm under the assumption that the S4, even though externally powered, still takes more power than the HDD), so I switched which USB ports they were in. Still, the same problem occurred. So I tested it in my iMac desktop and, thus far, it has been working perfectly. So I returned the MBA and got a new one, thinking it was a defective one. Sadly, trying it again tonight with a new MBA of the same specs, the same problem occurred. So now, I am out of ideas. Does anyone know what could be causing this problem and, if so, how to fix it? I can still return my MBA, but I would really like to keep it if possible. It does everything else I want (for school and whatnot) really well. It's just having this one, very frustrating issue. Thanks for any help you can offer. If this is an actual problem with the MBA models, would it be best for me to wait to get a new MBP? Cheers.