I have similar issues with the LG Flatron. I've had it for about a month and a half. No consistent pattern of operation. It sometimes it will operate for hours without going to sleep. Next day it will go to sleep every few minutes. I have found that I can unplug and plug the power cord back in and that works for most of the times. Sometimes using the keyboard or mouse will wake it up. I can bring it out of sleep mode with touching the menu button on the side of the display and that will bring out of sleep mode; but, as soon as you release the button it goes back to sleep. I've tried analog and digital cables. What's wierd is my 5 year old daughter jumped next to me (up stairs) and the monitor went into sleep mode with her landing on the floor. Just for grins after "waking" it back up I thumped the monitor with my finger and that put it to sleep. All cables were firmly attached to the monitor. I've taking my computer into a shop and had it looked at. I thought maybe the video card was messed up. The computer shop didn't find anything wrong with the computer. I'm going to call the LG technician and see what they have to say. Otherwise I'm going back and getting a different brand of monitor.