My Nexus 7 used to work fine in Windows 7 64bit, but now all of sudden when I connect it, it shows me the new device screen, it shows in Eclipse/ADB as Nexus 7 with Android 4.3 (correct), and then disappears a second or few later, with Device Disconnected in ADB log.
ADB then reports it as 'Offline' with OS unknown.
I have tried three different USB cabled, different USB ports, and on my Mac (not my main dev device though), the device works well. This is really frustrating. I tried setting the connection to PTP and Media Device. Both don't help.