I got 2 screens plugged to my HD5670, a 18,5 inch Philips LED and a 32 inch LCD Toshiba TV.
The thing is something strange happens with the image displayed on the LED monitor, when I turn AMD Overdrive on.
At first it looks normal, but when I scroll web pages up and down I can see black bars like the screen's tearing up.
It also happens in few games.
It's like there's something wrong with the screen refresh rate.
The odd fact is I can only see it on the LED display and not on the LCD TV.
The GPU is running cool and I do not encounter any graphical glitches or artifacts with Overdrive off.
I remember using it with a single screen, before I bought the TV and the issue was not present.
Could this be a driver issue, can't remember if I updated it since then..
It's not really a problem, since I can use the card without it.