Even though I've set the monitor to never sleep, it does at least once a day.  Then when I try to wake it with mouse or keyboard, the screen flashes back on for about one second then goes black again.  It then fails to respond to any device until the power is turned off to the monitor then restored.  The monitor will then again flash to life for about one second before going black again.  The only solution I've found is to restart the computer.  I'm running a new Dell XPS with Windows 7.  Any suggestions?