The HDTVi DVR's have limitations due to available resources. It can be overly complicated as both "Enhanced IP Mode" and "Enhanced VCA Mode" affect capabilities as does the firmware version. There won't be anything wrong with your DVR, you'll just have maxed out its capabilities. Those limitations aren't there with IP systems, as most processing is carried out in the camera itself.
It's a HDTVi system with DVR so there's no firmware upgrades for the cameras. There's also no web interface for the camera, just the ability to alter a few camera parameters over a menu accessible via the coaxial telemetry. All event setup is carried out in the DVR but certain combinations of settings are restricted.