I have a tidbit that may help solve the problem.
Win7 x64, Catalyst 10.2, 2x 4890s.
When crossfire is enabled, taking pictures produces white pictures - when crossfire is disabled, taking pictures work. Viewing pictures existing pictures doesn't seem to be affected.
Because you're seeing this on a 4870x2, it makes me think that there's a same root cause to both issues.
Edit: Catalyst 10.3 with crossfire application profiles lets capturing pictures work with crossfire enabled and D3DOverrider running. When taking off and then landing, I heard another 'chime' from D3DOverrider changing it's mind over what I was running and the game slowed to a crawl.
Launch game. Chime.
Load game where I was at a planet. Chime.
Go to ship, take off.
Land somewhere. Title of planet. Chime and see planet. Game slow.
Taking off, it's fast. Landing again. Chimes and still slow. PDA is fast while rest of game is slow. Holding esc to go to the main menu is slow.
This also happens when you load a game when you're landed, exiting to menu, and then loading the game again.
Methinks there's something about crossfire and triple buffering override settings. Will do some more poking.
edit2: More poking and results:
Catalyst for all modes: OpenGL triple buffering checked, vertical refresh set to always on, AA and AF at application settings, mipmap at highest, AAA off.
D3DOverrider off, Crossfire disabled, Catalyst AI advanced - doesn't slow down, pictures work
D3DOverrider on, Crossfire enabled, Catalyst AI advanced - slows down, pictures work
D3DOverrider off, Crossfire enabled, Catalyst AI advanced - doesn't slow down, pictures don't work
D3DOverrider off, Crossfire enabled, Catalyst AI standard - doesn't slow down, pictures don't work
D3DOverrider off, Crossfire enabled, Catalyst AI disabled - doesn't slow down, pictures work