try using the other DVI plug on your video card, sometimes I have that too, especially since I started running 2 video cards. I mean when it works it works solid, but when you switch the DVI<-> monitor plug on video card (e.g. between DVI-I vs DVI-D or between video cards) especially on running system then the black screen welcomes, once or twice I saw it at startup too after swapping ports on cards (or between cards, can't remember). 600 series video cards you running perhaps? they can do that to you sometimes ...
.: R3C0NF1GUR3D :.ASUS MVE :: 3770K bench @ 5.2GHz (delidded) :: 2x4GB Mushkin 996990 @ 2400MHz CL10 @ 1.7V :: evga 670 2GB SLI @ 1280/7108 :: Mushkin Chronos 240GB SSD RAID0 (OS) :: WD RE4 2TB (storage) 2TB :: Hitachi Deskstar 5K300 2TB (backup USB3.0) :: ASUS VG248QE 24'' 144Hz monitor
My rig with pictures"We are what we repeatedly do. Excellence, then, is not an act, but a habit." - Aristotle