I upgraded from my cpu's integrated graphics (Intel Q33 Express Chipset) to an ATI Radeon HD 3470. My monitor, which worked fine before on an RGB connection, is now display red and fuzzy on a DVI connection.
I should mention that I upgraded because the integrated graphics weren't compatible with Windows 8. Obviously the new one is. Also, I took this graphics card out of my mom's work computer, in which it worked fine with this monitor. All my drivers are up to date and I even tried reverting them to see if that fixed the problem, but of course it didn't.