primary monitor goes black periodically

I just did a clean install of 13.2
Video card is NVidia GEForce 210 running Nouveau drivers;
Monitors are: Acer H236HL running at 1920x1080 and a Samsung SyncMaster912N running at 1280x1024

50-moniitor.conf, 50-device.conf, and 5-screen.conf are all empty.

Configuration for the monitors was done through Configure Desktop, Monitors and Displays and seems to work EXCEPT the Acer screen periodically goes black. When the Acer goes black, the Samsung monitor continues to work as if nothing is wrong. The Acer will stay black for a few seconds, then come back on. There don’t seem to be any distortions to the video when it comes back. There doesn’t seem to be anything that “triggers” the failure.

cvt -q reports:

Screen 0: minimum 320 x 200, current 3200 x 1080, maximum 8192 x 8192
DVI-I-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 509mm x 286mm
   1920x1080     60.00*+  50.00    59.94  
   1680x1050     59.88  
   1280x1024     60.02  
   1440x900      59.90  
   1280x800      59.91  
   1152x864      75.00  
   1280x720      60.00    50.00    59.94  
   1024x768      70.07    60.00  
   800x600       60.32    56.25  
   720x576       50.00  
   720x480       60.00    59.94  
   640x480       66.67    60.00    59.94  
   720x400       70.08  
VGA-1 connected 1280x1024+1920+0 (normal left inverted right x axis y axis) 376mm x 301mm
   1280x1024     60.02*+  75.02  
   1152x864      75.00  
   1024x768      75.08    70.07    60.00  
   832x624       74.55  
   800x600       72.19    75.00    60.32    56.25  
   640x480       75.00    72.81    66.67    60.00  
   720x400       70.08  


I was thinking of adding the following section to 50-monitor.conf - do I need to add anything to the 50-screen or 50-device files since the Acer uses HDMI?


Section "Monitor"
  Identifier "Default Monitor"
  VendorName "Acer"
  HorizSync 50.0 - 60.0
  VertRefresh 60.0 - 70.0
  Modeline "1920x1080_60.00"  173.00  1920 2048 2248 2576  1080 1083 1088 1120 -hsync +vsync
EndSection