I just got this monitor, and it has a couple of strange vertical lines around 1px wide each, one on the far left of the screen and one center-right. It's barely or not at all visible on brighter colors like white, red, yellow, but its VERY visible on greens, blues, greys, etc. It happens no matter which type of hookup I use (DVI or VGA), and it doesn't change with either type or with changing the screen resolution. I'm on Windows 7 and my video card is an AMD Radeon HD 6670, not overclocked at all. I also have a few unrelated dead pixels but they're not a big issue and I doubt they're related.
Edit: Forgot to mention, even though it seems to be more visible on darker colors, it's not at all visible on black because the line itself is black/dark colored. There are a few more much lighter lines on other parts of the screen too, but they're so light they're almost unnoticeable except on deep blues and greens.
If the issue appears when running the STFC (Self-Test Feature Check), it is defective and should be replaced. We do not repair monitors, we simply replace them while under warranty.