We've done some long time installations ourselves, but all of them have been with Kinect 2, and most of them have been able to run for some weeks or even months without problems (we have had some hardware break down and some problems with Intel GPUs, but not with the sensor itself).
Both the Kinect variants do have their own power supplies, so I don't think they draw power from USB at all. It's the USB bandwidth that could be the problem, if the Matrox is bandwidth-hoggy. Yet I doubt this would appear over a long time period such as 30 minutes - if the bandwidth was a problem it should manifest as a USB disconnect rather fast.
Is the crash you're talking about a crash of NI mate itself, the sensor program, or the USB connection to the sensor (the log window would mention this)? If this is a crash of NI mate itself, could this be a memory problem? Perhaps there's some memory leak we haven't heard about, or perhaps the Log window is being filled with too verbose logging?