pixels disappearing moving between multi monitor screens

[MILESCFA]

Attached is a picture of my multi monitor display setup with an application spanning two HP monitors. Note the "black line" delineates the two screens. I have 4 screen shots in the pic, shifting 1 pixel at a time between the screens.

When I have a screen stretched over/spanning the HP V242h and a HP LV2311, about 2-3 pixels "disappear" between the overlap. This does NOT happen when the same application is stretched across two HP LV2311.

FYI my monitors are a square 2x2. I have a GeForce GTX 660 Ti and a (same but) 560. As it happenes my bottom screens are attached one to the 660 and one to the 560, thus so are the top 2 screens.

On older screens I recall having a control to shift the whole screen/image left, right, up or down, but the HP V242h "image adjust" control is greyed out. No other monitor setup menu option allows me to adjust the screen, and I even tried resizing using the GeForce control panel, but I actuall lost 1-2 MORE pixels doing it this way.

So everything seems to point to the HP V242h being the problem.... at least on this computer; however, i have another computer with with one HP LV2311 and then 3 monitors from other manufacter. These same problem exists, but not between the other manufacter's screens, but it occurs on the HP LV2311 this time.

I've had both these this setup a long time and just noticed, so it is easy to miss. However, the screen shot i include is an indicator on stocks and since the "signal" is onyl 2 or so pixels wide, I could miss osmething critial.

Any ideas as to how to fix?