Wow, so I wasn't crazy - exactly the same thing used to happen to me when I got up from my Markus and the screen would turn off for a second. My hypothesis was

Wow, so I wasn't crazy - exactly the same thing used to happen to me when I got up from my Markus and the screen would turn off for a second. My hypothesis was a loose cable which I bumped slightly, but not touching the table when getting up didn't work. Not sure why, but it eventually went away.