ohaider,

Test the both the VGA and HDMI ports from the monitor to your computer using VGA to VGA cabling and then HDMI to HDMI cabling. No adapters.

Using both, boot the computer into safemode. Does it ever flicker?

I'm running of HDMI only, but the HDMI cable worked just fine with everything else. Thing is I have two monitors, and when I replaced the other one with this one both monitors now flicker and I can't seem to tell why. However, when the 2440l blacks out the other doesn't. The video card I'm using is only a couple months old but I guess could possibly have a faulty port, but it just doesn't seem likely imo.

Is the computer a laptop or desktop? List all the ports on the video card.

It's a desktop. I've got a msi N660 Ti PE GeForce GTX 660 Ti 2gb. It's got two "dual-link DVI' ports and HDMI. It also lists "DiplayPort 1.2"

I'm having the exact same issues on the exact same monitor at tthe exact same time (around February 12th).  I thought it was my Nvidia GTX 660 acting up after some bad driver updates from Nvidia (quite common it seems).  For good measure, I did a COMPLETE CLEAN OS install of Windows 8 and used old 306.97 drivers from Nvidia.  The problem seemed solved for a while until the black screen returned!  It appears as if the monitor lost input for a split second and had to refresh!

After reading this thread I went to the device manager and rollbacked the 2440L driver to its previous version (Windows had suggested an update, sneaky little...)  The Dell Driver it installed indicated it was on the release date of 6-10-2012, now I am on the rollbacked/previous 3-22-2012.  Both drivers say they're ver 1.0.0.0 (What? Name/number your drivers for god sake!)  This seems to have fixed the flickering which happened terribly in fullscreen video and games.  If I try to disable the drivers, Windows 8 features such as the charm bar and other shortcuts (like Win+X) don't work on the dell, but only on my second monitor (an old LG monitor).  Windows is also reinstalling the new drivers automatically!

Dell your new drivers are   up the monitors!  It was difficult to diagnose this because similar glitches happen with video cards.  I hope this helps someone, including the original poster.  Fix the drivers already.

Glad to know I'm not the only one experiencing this, although I am sorry cause it is quite annoying. Especially since there isn't really a way to contact Dell since they require a support tag and it doesn't have one. It's one of the most frustrating customer experiences I've ever had. It's a beautiful monitor but I don't like having these problems.

I just rolled back the driver to see if it helps, and if it does I'll do an update if the flickering/blacking out stops. Thanks!

I hope this solves the issue, right now I'me running through everything I can think of that could have been causing this.  In Nvidia's control panel I set "Adjust Desktop Color settings" to Desktop only.  I set the 2440L's input selection to HDMI and not Auto Select (just in case it might jump to VGA).  I'm also experimenting with the driver versions, and disabling them in certain orders while testing content.  I can't do much now because of my busy schedule, but I'm gonna run this through the grinder and try and reproduce the flickering consistently, then find out what exactly is causing this.  There is not much information out there right now about this problem and it seems only you me, and one other person with an S series on this forum have experienced this.

And agreed!  This is a fantastic monitor.  I'm a digital painter and its color correctness and contrast is exceptional for the price.  I love everything about it.

Here are my system specs:

i7-3770K

Gigabyte Z77x-D3H

Nvidia (MSI branded) 660

Nvidia drivers ver.306.97

Monitor Driver date 3-22-2012

In Nvidia control panel I have:

the control set to send "Desktop Only" to the 2440L.

I have Inverse Telecine turned off

I have uninstalled the Dell monitor management program, it seemed to work at first for you until the problem reappeared.  I don't think I'll re-install it, even though its pretty handy.

On the monitor I have "HDMI" selected not "Auto Select."

So far absolutely zero flickering.  I haven't been able to reproduce it.  I think this is all stable for me now, I hope its solved for you too ohaider.

Still having troubles. Just turned off the inverse telecine, changed to "HDMI" instead of the Auto, rolled back the driver, and have the monitor software uninstalled. I didn't see where the control set though, hopefully this will keep it from flickering/blacking out.

*Update*

Problem is still persisting =/. I don't flicker as much, but it still happens and just had another black out.