S2440L power saving mode issues

I purchased this monitor three weeks ago and for a week it worked great.  Then it would go into "power saving mode" and would not come back on and locked up my pc to the point where to reboot I had to turn off/on the switch on the surge protector.  Sometimes I had to do this 2 or three times.  I took the monitor back to Best Buy and they traded it out for me.  Same problem.  It would also just blur the picture into a bunch of lines of colored dots.  So I went and bought a straight HDMI to HDMI cable thinking that would solve the issue and it appeared to do so - for a while. In reading this discussion board, it sounds like Dell has manufactured a lemon and is still selling it without any resolution or fix to the problem.  I am thinking that if it is left unattended for any length of time that when it times out, that is when the problem occurs.  So if I have to be away from the computer for any length of time, I shut down completely and then reboot the entire system when I get back.  Needless to say, this is most inconvenient.  .  Let's see if Dell responds to me on this - HA!