I know ATI 6850/6870 and newer cards have a tearing issue when DVI/HDMI and DP are used at the same time. In my 3x 24" setup, the DP-to-DVI monitor has a tear that slowly cycles it's way up the screen. It's a product of slightly different timings, where the DP port runs a perfect 60hz, and the DVI/HDMI ports run at 59.XXXhz. Under strictly DVI/HDMI, there should be no such issue rooted in the card itself.
So, in an effort to fix a tearing issue related to two DVI ports being used, I would look at the your refresh options. If I were to guess, I'd say that the receiver is reporting 59.XXXhz support, and reporting 60hz as not supported, regardless of what the TV actually supports. The monitor I'm guessing is reporting 60hz compatability, and possibly 59.XXXhz. So, receiver at 59hz and monitor at 60hz, the card does the best it can and tears one of the outputs.
Hunt down an 59hz option for both outputs.