I have the 8ch Super Mini NVR (N6200-8E) with 2 x ELP 1080p camera+audio that records onto 1TB 3.5" USB drive on powered hub.
For the most part it's pretty good.
I "occasionally" have the same problem as the above.
Initially I thought that the problem was because I was recording continuous at 10fps.
The description of the backup AVI file says it is 25fps?!? how can this be with 10fps camera footage!
So in a 1 minute backup I would get ~25secs of video that was video played fast and always 60secs of audio at normal speed where the video just shows a "still" of the last frame for the remainder of the audio.
So I upped one camera to 25fps.
This seems to fix the problem "some" of the time.
So some of the backups would be fine where audio and video were in sync and went for the correct time at the correct speed.
Other backups I found the video was fast as before with normal speed audio.
I'm sure the Police don't appreciate me handing them a video that looks like an extract from the Benny hill show
Currently my NVR has 20140417 firmware
I don't know if this issue is actually resolved in firmware since nothing further was said from Mike or GhostRider.
To me if I record 10fps the AVI file should come out 10fps.
I did try post separating the streams, slowing the video then recombining them but that is a LOT of work!
Another thing that annoys me is there is no Audio out.
I still wonder why there is a volume adjust bar and a mute button for the playback screen
I have the NVR connected to my TV via HDMI.
I can connect a PC to the TV via HDMI and audio works fine.
So that eliminates the TV, connector and cable - leaving - you guessed it the NVR!
Where does the audio come out???