I have just installed a Gigabyte Radeon HD 6950, and I'm having an issue with extending the desktop from my ASUS montior (VGA) to my Vizio HDTV (HDMI).
Both CCC and Windows are recognizing the EDIDs of both devices, but I can only swap desktops. Whenever I try to duplicate or extend the desktops CCC and Windows 7 the errors are something along the lines of "Cannot complete this action", and "Cannot save this configuration" respectively. I upgraded from an Nvidia gt460, and had no issues at all with dual monitors.
I am not sure if it's a hardware issue. As far as software goes, I've uninstalled CCC, deleted/reinstalled the latest drivers, custom installed with only the essentials from Catalyst downloader.
Windows 7 - 64 bit
Gigabyte H67MA-USB3-B3 motherboard
Intel Core i5-2400 @ 3.10 GHz
16G DDR3 SDRAM
Gigabyte Radeon HD 6950 1GB
ASUS VS Series LED backlight LCD