jaguarskx :
Ouch. Definitely not good.
My only guess is that something one the circuit board has malfunctioned. Is your Dell U2410 still under warranty?
Unfortunately it's not under warranty any longer. It started in the middle of a game, and I thought it was my GPU or cable at first. But I've seen it on other sources as well, and it cuts out the monitor's menu. It happens very randomly, and sometimes I get random lines that flash the top of the screen.