Try running openGL in windowed mode, with a small window - that should let you see if any error messages pop up in a dialog window. If it's really just a black screen with no errors and no sign of the game working nor actually crashing, I think it might be openGL indeed - but Pierre or Pedro can probably tell you how to run a test to be sure of it.
Actually, I did get that effect on occasion when I first started (the experience was complete with the "System Error" Windows sound), but it stopped after a while. I hate errors which are difficult to reproduce. Makes it so difficult to pin down the cause of problems.If it's really just a black screen with no errors and no sign of the game working nor actually crashing, I think it might be openGL indeed...