With a reboot flag of 00x01, it isn't an auto maintenance restart.
Here is some steps you can take to eliminate if it is a power issue:
1. Remove all cameras from the unit. If there are HDDs in the unit, remove those. Let the unit run for an extended period of time and see if there are any reboots.
a. If this corrects the issue, then more than likely it is either the wall outlet not giving out enough power to the entire setup OR one of the HDDs are going bad. Test the HDDs on a PC (an external enclosure comes in handy for this) to see if they have any errors. There are quite a few free SMART and HDD diagnostic software programs to be found if you Google for them.
2. If it still reboots, try plugging the unit directly into a different wall outlet. Do another extended test.
3. If it still reboots, try a different power adapter for the DVR.
4. If at this point it still reboots, it is probably is a bad unit. Many of these units are rated for about 131°F. Make sure you aren't letting it run in an high temperature environment. Physically check the unit for heat after the test by putting your hand on the bottom of the unit. You can tell if it is overheating. Also smell the unit, sometimes you can tell if the board has been fried.
Firmware sometimes may correct the issue, but from my experience, a rebooting or freezing unit is usually a power issue or a faulty main board issue.