looking at the screen on my KDS 19" CRT. every so often the display will wiggle ever so slightly. It is so minute that you have to really watch for it and it is not doing this at regular intervals. I have been using the current video settings for the life of the monitor, about two years. The video card, an Asus 5900 ultra, is app. 3 yrs. old. Anyone have any suggestions as what is going on?