@andrasfodor could be but it's unlikely. Once it has been on for a while, does the picture turn all clear? If so, then this could be either a bad solder joint or failing capacitors etc. WE really would need to see the circuit boards etc. which may show some damage. Also, if you have a thermometer, you could measure the temp on your GPU. Based on the symptoms your describe and the display error, my first suspect here is actually the main board.
BTW nice monitor! :-)