Well I seem to be having a similar problem.
I just bought a 9CH MPEG4 DVR running Linux from ebay. It doesn't seem to have a model number but from what I can work out the insides are the same as the Q-See model QSD6209.
It seems to work fairly well until you start trying to use the PC Viewer software over the network. The software seems to work initially then after a while I can't connect to the DVR anymore. I get the same error message "(-3) No Stream time out" when trying to connect. The DVR is usually still working OK but sometimes I find that this has also crashed. In any case the only way to get it the network working again is to reboot the DVR.
The problem seems the same regardless of if you are connecting over the internet or you are on the local network.
I suspect the problem is a Linux firmware issue in the DVR although it seems to have the latest available firmware version.
Does anyone have any ideas?
Also eebozz, getting back to your issue. What brand or model is your DVR?
