Which channel number is the stream you want to connect to on the new camera?
I had a similar problem trying to connect a Chinese 2MP camera onto a system using an NV5000.
The problem I encountered was that I needed to connect to stream 0 for the 2mp feed, but could only get the low res feed on channel 1. The only option in the drop-down box when setting up the camera on the Aver software was channel 1 and it used that regardless of what I put in as the stream URL.
I mailed Aver and they said 'we know about it, other people have the same problem, there isn't a fix for it, use another camera from our approved list"
Rather than resign myself to spending twice as much on cameras I had a poke about in the configuration files and found a fix.
My camera used RTSP_TCP so I opened the TCP.ini file in DVR_Server\IPCamSDK\RTSP_TCP and changed the 1 to a 0 for 'ChannelNum' in the 'CHANNEL' section. (Make a bakup of the file first if you try it)
This resolved my problem, but be warned that it would change the setting for all the cameras using the RTSP_TCP connection.
It still shows 1 in the drop-down box, but actually uses 0.
Maybe that will help you too? I mailed Aver to let them know it may help those other people, but didn't get a response.