I am also experiencing random disconnects from a newly purchased DCS-2630L.
I have it connected to DSM6 surveillance station, and about once per 24hr perioid at random it disconnects. More often then not, the admin web page becomes unresponsive at this point, and I have to power cycle the camera.
This is definitely not a network issue (5ghz, now trying 2.4ghz), as no other devices are disconnecting, and even if it was an interference issue, the camera should instantly recover.
I also have audio detection only enabled with a custom threshold (80dB) for "motion detection" (no motion detection area is set)